June 1948, Berlin. Ever since the end of the war, three years before, tension had been increasing between the Allied military government and the Soviet bosses of East Berlin. The Cold War was becoming war. Two and a half million people, more than half of Berlin's population, lived in the American, British and French zones. But the whole city was surrounded by the Soviet zone of Germany. Supplying the two and a half million people of the Western sectors was a system of rails, canals and roads. Suddenly, the Soviet military government in Berlin clamped down a land blockade of the Allied sectors of the city. The suspension of all traffic successfully blocked all surface access to the city. The Soviets claimed that technical difficulties caused the suffrage. The truth was that they were trying to force the Western Allies to surrender their position in Berlin. And the weapon was hunger. The occupation personnel of the Western nations, both military and civilian, along with the two and a half million of the German population, were threatened with starvation. What were they all going to do for food and fuel? With all the arteries into the city closed, Berlin was paralyzed. With the fuel supply cut off, there wasn't much electricity. Nearly all of the lights went out. The Allies made an important decision to hold Berlin. In late June 1948, General Curtis LeMay, commanding general of the U.S. Air Forces in Europe, started the airlift. Our all-out effort began on the 28th when we airlifted about 300 tons. From airfields like Rhein-Main near Frankfurt, we flew the air corridors through the Soviet zone to Tempelhof Field in Berlin. The airlift was our first important use of air power as an instrument of national policy, according to Secretary of the Air Force Simington and General Vandenberg, Chief of Staff. General Lucius Clay, our European Commander-in-Chief, joined in accepting the challenge. The call went out for cargo aircraft from all parts of the world. From the Caribbean, from Texas, Alaska, Hawaii, Panama, troop carrier squadrons sent C-54s. And before long, mats was sending them too. In the States, Westover was our jumping-off place for airlift planes preparing to span the Atlantic. The combined airlift task force headquarters was established at Weesbottom. The entire operation was now in business in a big way. Army, Navy and Air Force, working together gave an inspiring example of joint action. And we mustn't forget that the British and the French gave much help. Headed by General William Tunner, who had been in charge of the aerial supply missions over the hump in Asia during World War II, the airlift task force was ready for a long haul. Pouring supplies into Berlin and bringing out manufactured goods. Rhein-Main was the chief air gateway of the corridor to Berlin. The Army Transportation Corps moved supplies in from ports and railheads in 10-ton trailers, about the cargo capacity of a C-54. Coal from the Ruhr, flour from our Midwest, sugar from Cuba, coffee from Brazil, butter and milk from Denmark, and many other supplies from many other places. Berlin's minimum daily requirement was about 4,500 tons of supplies. For several months in 1949, our deliveries averaged more than 7,500 tons a day. The Air Force assigned more than 300 airplanes and more than 20,000 men to the airlift, and Britain made a large contribution of both aircraft and personnel. It was an operation without precedent and a severe test of precision flying, of logistics, maintenance, communications and weather service. Some of us had bombed Berlin, but now we were trying to keep the same city alive. It meant that we had to get more from each airplane and from each man than ever before. Takeoffs with full loads were three minutes apart. The air corridor to Berlin was narrow and dangerous. With 40 to 50 airplanes going to it simultaneously, they had to be accurately spaced. And until the late stages of the airlift, they were flown at five different levels, the levels being 500 feet apart. This called for extremely precise air traffic control. Here the position of each aircraft in the constant stream of C-54s was flooded and re-plotted. And every three minutes there was a landing at Tempelhof, the Berlin Air Terminus. Each aircraft in Operation Bittles flew three round trips every day to Tempelhof, or to the other airfields in the Allied sector. At the end of the line, volunteer crews of this place persons were always on hand to unload our aircraft. And it took an army of them. At the height of the airlift, the control tower at Tempelhof handled more than 400 landings and takeoffs every day. Seven days a week, around the clock and regardless of weather. Operation Bittles really gave us in 15 months as much experience in air transport as we ordinarily get in 10 years. When bad weather arrived in the fall, everyone was put to the supreme test. Rain and heavy fog day after day. The communists expected the airlift would be broken, but it wasn't. We kept right on. Army Airways communication system operated a network that fed information to ground control approach at Tempelhof. Rotating GCA antennae tied air and ground together. GCA operators, at radarscopes 24 hours a day, talked us down at the rate of a landing every three minutes. Baker George II, this is the final controller. Remain on receive for the remainder of this transmission. Maintain your present elevation and continue Vector 3-1-5. You're almost at the glide path. Begin your rate of descent at 500 feet per minute. By starting down the glide path, a rated descent is good. Asmuth is gone. Very nice flying indeed. Maintain your heading on course, on the glide path. Very good. Now over the end of the runway, Asmuth and elevation both perfect. Touchdown in four seconds. We used a good many C-47s. But for an operation on this scale, they were too small and too slow. So the C-54s took over. We soon began setting records, and then we broke them as fast as we made them. Coal was vitally important. We had to fly it in if there was going to be any heat or light or power in West Berlin. The coal came from the roar and was sacked in war surfless duffel bags. We saw to it that every bomb was put to good use. Berlin was saved because the airlift kept the fires burning, kept wheels turning, kept the ovens going. Not long before, we had been delivering bombs to compel peace. Now we were delivering bread to maintain that peace. The airlift cargoes kept the city alive. Before Operation Vittles, Berlin was one of the places where children cringed in terror at the roar of airplanes overhead. The airlift planes taught them they need cringe no more. In 15 months, the airlift brought in two and a quarter million tons of supplies. Light sustaining necessities. The greatest feat in transportation history. Achieved by the RAF, the United States Army, Navy, and Air Force. Meanwhile, in this building at Fort Worth, Texas, another great Air Force achievement of a different kind was taking shape. The B-36, the first genuine intercontinental bomber. No aircraft had ever had a wing spread like this. 230 feet. That's equal to a distance from home plate in Yankee Stadium to a point over 100 feet beyond the second base. No bomber ever had such tremendous fuselage space. From nose to tail and from wall to wall, the equal of 10 good-sized living rooms. The B-36 was first conceived in 1941. And by 1946, she was ready for her first test flight. Big wasn't she. Her main function was to carry bombs. But she went up well-armed with eight gun turrets, each mounting two 20-millimeter cannon that could fire explosive shells as well as armor-piercing projectiles. That was more and better armament than any other bomber ever had. Being one of the most complicated engines of war ever built, the B-36 needed a crew of 16 specialists. Every one of them was a man of great experience and skill. And they worked together for long periods and achieved a high degree of teamwork. It was an honor to be picked as a member of a B-36 crew. And the man who flew the big bomber came to admire her. Talk about power. In the late stages of development, the B-36 had six piston engines of 3,800 horsepower each and four jet engines, each capable of 5,200 pounds of thrust at takeoff. The big bomber had a much greater carrying capacity than any other aircraft so far produced. There was room in the four big bomb bays for 100, 500-pound bombs. Or when tremendously big ones were needed, the cargo could be two bombs, each weighing 21 tons. With its fuel load of 21,000 gallons, the B-36 had tremendous range, 10,000 miles without refueling, and a combat radius of more than 4,000 miles. Even at great altitude and at more than 400 miles an hour, the B-36 was a steady flying platform, a stable and accurate bomber. Over the target. With its speed, armament, and high altitude capability, the B-36 became the strategic air command's Sunday punch. It gave the Air Force one of its best means of winning friends and influencing people. Largely because of this aircraft, the strategic air command was the first military organization in history that could assault the heart of a remote enemy country from stateside places within hours after the outbreak of a war. The B-36 proved to be a great airplane, and there was no question as to where it belonged, right where it was, in the United States Air Force.


Hey everyone it's Robert so I've gotten a ton of requests to finally do Haven. This is the last map of the Yodu lineup series that I have to do. I've done all the maps prior to this so if you haven't seen them yet be sure to check them out after this video. Because this is the last video of the series I'd hate to lose some of you guys that have been watching my past couple of videos with these Yodu lineups so be sure to stick around and subscribe. I'd love to see you guys here more often. It's free you can always change your mind. I stream almost every single day on my twitch account twitch.tv slash robberrayhards underscore playing some Yodu showing you guys some of these lineups that I do on all these different maps playing a lot of other agents as well so if you're interested in that all the links will be down in the description below. I hope to see some of you guys there. As you throw your teleporter out and the enemy gets close to it they can see it and they can also hear it and they can shoot it and destroy it so as you're throwing your teleporter out you're going to want to throw some flash bings and defend it maybe ask for a couple smokes from your teammates to defend it as well I can't trust enough how important it is to defend your teleporter as it's going out otherwise the enemies are going to find it and they're just going to sit on it and camp it and wait for you to come out keep that in mind as you're using some of these lineups in your own games so this first lineup I have it's going to get you from this corner all the way to the back I like it a lot because you don't actually have to peek in order to throw it out get as deep as you can into this corner and then you see this like stone coming up into the sky here just aim just to the right of the corner of this stone just where your cross is barely not touching it and then throw it out and get you back into the corner of seaside this next one is probably my favorite one throughout the entire map all you have to do is flash your cross get into this corner and it's going to get you from this corner all the way to the enemy spawn now by the time it gets there your teleporter doesn't have much time so just pay attention to that as you're using it but you just want to get in this corner here aim along the edge of this cubby wall it's not that precise it's pretty easy to hit throw it out and look where this goes and for the most part it's pretty safe unless you have somebody playing logs get you all the way in you again you can pop it at any time but it gets here you can TP in next I wanted to go over ace sites now ace sites kind of a tricky one because there's such a harsh angle here in short and then also the problem is as you throw out your teleporter long it actually gets clipped and stopped on this wall right here so it's a little bit tricky to work with but I have a few lineups that I want to show you guys anyways this first one's going to get you from this plant just go as far into the plant corner as you can and then you're going to want to aim at this dark brick here on the wall and it's going to get you from here all the way into under heaven right by this box a little vulnerable but if you have smokes and flashes again nothing you can't handle throw it out and surprisingly from that angle it gets past this clip on the wall took a took a while to get that lined up but it gets you right here under heaven this next one I like as well because a lot of times when people are holding a they're usually holding it from heaven or they're holding this box like holding this angle like this and this one's going to get you into this corner here so you can actually TP to this corner and then swing out and look at them box they're not going to expect you to be on that corner right there so you usually have the jump going into it but you're going to stand up against this plant just like the last one and then aim just along this doorframe here pretty easy to hit it's going to go all the way down and again unless they're standing like right here they're not going to see the TP so you should be safe TP in this next one I like a lot you can play a lot of mind games with it the scenario that I like to use it the most in is let's say the bomb is planted in default right and now you're playing long I like to sit up in this brick area and then throw the teleporter out it's going to get you from here all the way under hell what you want to do is just aim it you see this small brick in the wall here just aim just underneath it about the middle throw it out it's going to go into hell and then I like to drop some like footsteps and then as it's going in you know maybe like flash your teleporter in let them know you're playing long right like really commit to it hit your footsteps TP heaven they think you're playing long still really mess with them this next one's going to get you from this corner here all the way into CT spawn and it's really good if you guys are doing like a hard A push and you want to catch the people rotating from C off guard you just want to get in this corner here and you see on the wall right where like it starts to arch up right right in the middle of the arch just throw your teleporter out it's going to go through site you're going to want to do this one quick again you want to catch the rotators before they can get there it's going to go all the way into their spawn and now you're right here ready to catch the rotators this next one is not that useful but it is possible and I wanted to share the information with you guys anyways in case the situation arises where you can use it so it's going to get you from short all the way into hell here the reason why I say it's not that useful is because if you're this far up usually the guy playing short is going to know you're here anyways but you know maybe you can use it like in a post playing situation whatever you want to do you can get creative so just get in this corner here and then aim it along about this area on the wall it's not that precise throw it out go through site and get you deep into hell so when it comes to attacking on B site there's not too much you can do it's pretty limited and mainly because of the clip in the wall here and the clip in the wall here it prevents it from going really anywhere but like the back of the site and even then your teleporter stops in the wall about here at max distance so there's no lineups that can get you to a link or to see link at least none that I found and I've been on the map for about two hours now looking for different lineups for it there is one pretty nice play if you can get up this close that I wanted to show you guys though maybe you can get like a brim or almond smoke down here walk up get into this corner on the ground here on this brown trim there's like a crack in the wall just aim your teleporter at this crack and it's going to get you from here about halfway up heaven stairs so it's a really nice flank if you can pull it off and you can catch the people before they see it on a link just throw it at this crack like I said it's going to go through and get you into heaven when it comes to teleport lineups and playing through garage there's not a lot of teleport lineups you can do and mainly because let me show you really quick so you can see it gets stuck like on this brown trim area for some reason so it's not actually possible for it to get out onto sea sites at least coming from the grass area so garage is kind of a dead zone when it comes to teleport lineups but that's not to say that yoru is bad at playing garage you know he is an entry fragger so you can get a nice flash off you know peek in and do your thing just when it comes to actual lineups with his gate crash ability I wouldn't worry too much about it all right let's get started with defense now I think you guys are really gonna like some of these defensive lineups now I know we just talked about attacking into garage but there is one for defense that I like a lot and what you want to do is just get up along these stairs here and you see this x on the wall if you just aim underneath this x or at the x itself you can throw it out here and it's going to go through hit this box and get you into this area and so the people grass as long as they're flashed once like this right as it's coming out you can actually teepee here and they're not going to have any idea you can also have your teammate smoke mid window for you what you can actually do is throw out a second flash swing it and this will usually get you a killer too there's another play you can do from garage that gets you from garage all the way into their spawn it's a bit risky if there's anybody playing grass they're definitely going to see your teleporter so just be careful while doing this but you can hop on the first step here and then aim at the white diamond at the top of like this red design here right in the middle of this white diamond and throw your teleporter out and look where this one goes this one's pretty cool it's gonna go through and get all the way into their spawn see long there's two spots your orb can go there's one that can go into cubby and this that's a pretty obvious play literally just don't up against this wall in any aspect it's gonna go down hit this staircase and go up and the other one you would just aim at this wall and it's gonna go down into this corner here but I wouldn't really bank on those two plays because a lot of times when people are pushing C they check these corners you are certain that they're not going to be playing C at all this round you're kind of just anchoring here just in case they do you can hold C throw your teleporter up against this wall somewhere you know just sit around maybe make sure they're not pushing C this one's going to go all the way into your own spawn so the second you're sitting here you're like oh they're pushing a they're pushing a utp and now you're right here ready to play with your team on a site so when it comes to defending B there's actually two plays that I have for you guys you're going to want to get a smoke on window for both of them otherwise these can be more risky than they already are because they're already pretty risky plays as it is but one that I like is you get a smoke down the window like I said throw it up against this wall anywhere and you're going to want two flashes for this you flash the first one as it's entering in and then flash a second time TP that's going to get you to the back of grass here and as they're getting flashed from your second flash you can usually get a killer too really make sure you have two flashes while doing this play another one you can do that seems a little obvious but surprisingly it still works in a lot of matches for some reason you can throw your teleporter out here again you're going to want the smoke window for sure that people in grass won't be able to hear or see your teleporter from there if you really want you can throw out a flashbang again you have the smoke window you just instantly crouch get behind the staircase and you can usually get like a pick or two that there's somebody playing grass just be careful because although they don't hear your teleporter as it's going out they can hear you TP to it so this next one is kind of unique but I like this play a lot if you have the mechanics for it so let's say you're pushing into heaven maybe it's a retake the bomb is down a lot of times the enemy is going to smoke you right and in this case the smoke is kind of doing you a favor but let's pretend for this sake that it's not so with this teleporter you can't actually throw it out of window on this windowsill anywhere you can throw it down here but it just gets stopped here but if you actually jump on the windowsill itself you can throw it down on the ground wherever you want so i can throw into this corner i can throw it down into a long and i don't think a lot of people know that yet and it requires a bit of mechanics but what you want to do is throw your first flash out and then as your first flash is going hop on this windowsill turn throw it out that way hop in this corner throw your second flash out tp and then deal with the guys on site another a defensive play i have for you guys it's kind of like a all or nothing play because once you commit to it you're committed to it there's no way out you're either gonna frag out or you're gonna die you definitely want to drop some footsteps before you do it in my opinion throw your teleporter anywhere along this wall and it's going to get you into this a lobby corner so if you're here they're pushing out of a what you can do is drop some footsteps throw out your flash tp to it and a frag out like i said in the beginning of the video i stream every single day on my twitch account twitch.tv slash chopper ray hearts underscore if you want to come through this is the final video to the yoru teleport lineup series that i have going i hope you guys have enjoyed all the videos so far all the rest of them will be linked down in the description below if you haven't seen them yet be sure to drop a like if you guys enjoyed and also consider subscribing like i said even though this is the end of this series here i'm going to be making a ton of valorant content that i'm sure you guys will enjoy i'd love to see you guys stick around and start building this community with me it's been a lot of fun so far and i've gotten a lot of positive feedback i think even like dot esports wrote an article on one of my lineups so if there's any other videos you guys want me to make you can leave a comment down below so hopefully i see some of you guys in my streams and in my future videos that's gonna do it for me thank you guys for watching i'll see you in the next one


to da je veliko pedagogisk vziv. V zelo se zelo zelo izvihne od vsoočenja. Tukaj je zelo s energijem, je to zelo, da je zelo, koncentrujno zeljene energij in 50 nr. v 1940. A bil ti ničt Trying that natural gas, petroleum, are going to be decreasing the consumption. There is decreasing the use of coal, and of course it is getting rITYce. But still for many years to go in decades we have to rely on fossil fuels. Which of course opens the big problem, because we know that these has a lot of consequence Tudi niče začali, da je tudi 50 rov in 50 do 2000 rov, da je vzvečnja vzvečne vzvečnja v CO2 in vzvečnja vzvečnja in tudi 100 ppm, ki je zelo jaz nekaj različ. Znamenimo, da dobro se vzvečnje vzvečnja vzvečnja vzvečnja, da znamenimo, da se vzvečnja vzvečnja vzvečnja vzvečnja vzvečnja. Tukaj ne lahko ne poživajo, ne lahko ne opravil, a tako da pridemo zelo zelo, če je to lepo, nekaj je zelo zelo obržen, nekaj nekaj nekaj kemika in nekaj nekaj nekaj spljenja. Tako je tukaj nekaj nekaj nekaj, da poživajem vsem. Ne꽤em, da se nekaj nekaj načo je izgleda, da je zelo prišel in je pošel in nekaj nekaj nekaj. Zato sem tukaj izgleda, da je to državno pravno stavlje. To je tega vsoša vsoša, da jsi ne zavljeliš diskussion o tem v nekaj nekaj nažal, ali na medija, da vse. Vse jih je da vse poštila, je tukaj razljavno izgleda, pa nisem si nekaj nekaj, da so nekaj pristim, da se ne poštila. Vesem, ta ideja in pravično, tudi ideja, že se vsoša je zelo zelo pošte, ker v prinesiplji lahko se početite CO2 in se reakvite s 3 molj, 1 molj CO2 in 3 molj z hidrogen in se predajte metanol in vod. Metanol je vsefjuel, je vsefjuel, je bilo konverter, ali je zelo vsefjuel vsefjuel. Vse proces je zelo vsefjuel. Vsefjuel je zelo vsefjuel vsefjuel. in rejuvala. Narednjih, da se počutimo, hidrogen je produsil industrijno v veliki mene, ali je produsil v poslutnih vsev. V procesu, kaj je izgleda stejne reformenje. In vse proces je nekaj zelo zelo, tudi nekaj plant v vsev, kaj je produsil metanol, izgleda z CO2. To je v 2014. To je basa na katalistu, kaper on zinkokaj, in je zelo na geotermalj energiji. To je zelo v Izlanu, ker je nekaj energij, in da je taj reakcij vzelo. To je tudi tudi termal katalizist. Zato vse je zelo energij, kaj je zelo na konverciju vzelo na eksternosti energij. Zato, kaj je zelo vzelo, ne binjo se načo zelo nekaj zelo ga kaj je zelo let v soli. Ciske, to je in zelo bila vzelo, ker CO2 je počkega instavna formda kareljina, kako njiha s počkom oxidico, je vkaj najboljših energijskih stajnih, zato termodinamik kljenjo. In zato s enami s hodim vzelo, da se vzelo, da igram vzelo zbredne in zelo, hrvom način nošu z vse boj gržovac, ki se prejdi in je zloženje doprav, zašeljaju nekaj ili neko v podstav inverteri. Vse je neko na konferenciji, ki mali da nekaj prejdi tising, večno neč nekaj reagirujemo vsakrana termodinamika, nekaj k seinem da neč nekaj prejdi מי filloves. Nisem s edmirationem, Vzdaj, kaj je bi bilo napotno, da sem bilo upril termodynamics. Tako je ni veliko, ni veliko dobro. Tukaj je svojezdi, ko je svojezdi s CO2 in fuel-ovnimi energijami. Vseš da se razstavila, da je bilo oto, da se to vzajča v prišločenu. Svojezdi, da imaš karboni, dioksaj, voda in vzajščenu vzajščenu. Vzajščenu vzajščenu, kaj bi začel se obrada vzajščenu, prej cannot convert this in glucose and oxygen. And since somebody has, I am sure he was going to talk about nature of photosynthesis, I will not address the complexity of this process, which are weather accustomed in nature and this is the result of a million years of evolution. Now, of course people are trying to design what is called the artificial photosynthesis. je to včešnja najbolj, da se je zelo naši dobroči, naši je nekaj, ki se je zelo v rojče, v ko je naši dobroči CO2, in kako je hodnjela, zelo naši dobroči. Včetno. Zelo našem pravda, da ima nekaj izgleden. Včetno, da, ki se zelo naši dobroči in nekaj, svarz izgleda energija za in izgleda tudi in zelo jaziljamo ljub. Vsih tudi je to tukaj o potopi katalizacij. Zelo ideje, ki me izgleda tako poni del, je vse občasno, lahko jaziljamo ljub in tudi stažimo elektron in vzelo. Tudi, kaj jaziljamo atom, jaziljamo elektron in jaziljamo zelo pozitiv. In tudi bolje bolje bolje, ki je separati v elektronici, to če in elektronici, moj držaj se nalivati na vsek. in reacijo s kamikvom vsek. Ko ni teči, naredite nekaj kamikv. To je ideja, ki je odlično. Foto katalizit se poživajo na 2 vrste. Because you can use these ideas of capturing light and generating electrons and holes on one side to produce what is called environmental catalysis. What is this? Well, you generate these electrons and holes, you have species which are pollutants which are in the air or in water, and you use these electrons and holes to transfer them to these molecules and induce chemical reactions and remove the pollutants. This is relatively easy because you want to go in the direction that thermodynamic suggests. So you want to reconvert molecules which are, for instance, toxic into CO2. In this case you want to produce CO2 because this CO2 molecule is not, is harmful for us. So we can use this to eliminate pollutants and it's relatively simple because it occurs with a single chart transfer.  Much more complicated is to basically use the same principle, generate electrons and holes to produce fuels, hydrogen or methanol or methane from CO2 and water. Because you need multiple chart transfers and you need to go against thermodynamics. So there are two fields which are both based on photoactive materials. One is environmental photocatalysis and one is production of fuels from solar energy. Now everybody is familiar, many people are familiar with this diagram but still I have to basically illustrate it because it is the basic of everything. So again, what happens when you have a nanoparticle, this can be an oxide, nanoparticle can be one of the most popular oxides, I will talk about this TIO2, but is in water, you have light, visible light or solar light, you generate electrons and holes. Are you generating electrons and holes? Because the material has some occupied states, the valence band and you excite an electron into the empty states, the conduction band. So the first requirement is that this jump, this transition has to occur in the visible range of light. First requirement, is that sufficient to make useful things? No, because then you need that the electron has to be transferred to the proton in water and the proton is reduced to hydrogen. And so you can induce the reduction of hydrogen or protons to hydrogen only if this electron is above the redox potential of water. And this is the second requirement. So the position of the conduction band has to be above this light. Then you have the holes. What can you do with the holes? In water, oxygen is in reduced state, is formally O2 minus. You generate an hole in the valence band because you have excited an electron. One electron is transferred back to the valence band or if you want, the hole migrates to the oxygen.  But this can only occur if the valence band of the semiconductor is below this threshold. And this is the third requirement. And you see, you need something which already has three requirements. And then if you generate this electron and the hole, they have to migrate to the surface of the nanoparticle. And in the process of migrating these electrons and holes, they can recombine, they can come together and basically fill the hole, the electron fills the hole and the process is stopped. And this is the fourth requirement. You need a low recombination rate.  So this is the basic. And how can we follow this process? Well, I'm not going to talk much about this particular technique which is called electromagnetic resonance or electron spin resonance. But you can follow the spin of electrons with this technique. And if you take, for instance, a TiO2 semiconductor and you take the spectrum in dark, there is no signal, then you irradiate your sample and you see there is a new signal, this signal which indicates the formation of O minus. O minus is radical. It has an unpaired electron. Or you excite electron into the conduction band and you form a titanium 3 plus ion. Again you have one unpaired electron titanium and you have another signal. So with this spectroscopy you can clearly see the generation of electrons and holes during your excitation process. OK, now, so if we have the right semiconductor we can start thinking of producing solar fuels. Hydrogen is the first of solar fuels. Of course many years ago, 20 years ago there was a lot if you go back in the newspapers. You will find that everybody was expecting the hydrogen car. In Milanova we wanted to build a gas station for hydrogen station. We still have the area. And everybody was convinced that hydrogen would have been the future. Actually that was not the case. Hydrogen economy would be fantastic because of course we could produce hydrogen from water and then use it in storage and use it for transportation and then using combustion and we regenerate water. So it's a very clean process. Today all the hydrogen which is produced doesn't come from splitting of water. It comes from steam reforming. So huge amounts of oil or natural gas are converted at very high temperature. For instance, methane plus water you form CO plus hydrogen. CO farther reacts with water and you form CO2 plus hydrogen. So when we produce hydrogen today we produce CO2 in the same way and we consume fossil fuels. And I visit one of these plants for instance in Ludvigshaven where Bayer has this huge chemical plant 7 kilometers wide, 2 kilometers large so in immense. And the first step they do is steam reforming. They produce a huge amount of hydrogen because hydrogen is needed for instance to produce ammonia which is another very important chemical reaction to produce fertilizers. So this is a problem. Today all the hydrogen is produced in this way. Of course you can produce this also biologically but the efficiency is low or in here we come to the topic photochemically and photo generation so you can use for instance in a semiconductor, TiO2 and you have light coming in and you generate these electrons and holes and you can produce oxygen on one side and hydrogen on the other side. And you can go to a web you can find many nice movies that show very clearly you just need this catalyst and you put it in water and you see the bubbles of hydrogen and oxygen coming out. The problem is that the efficiency is very low. Now this brings to the first problem which are the catalysts that we can use for this process, which are the materials. Now the first observations and a lot of literature is about titanium dioxide, TiO2. Well if you go again to the history you will find out that TiO2 is used since a century because it was used as an additive to paints already 1920. And already 1920 people realized that because it imposes optical properties of the paint so here there is a lot of TiO2 in this paint. But what also was recognized at that time that exactly because TiO2 is photoactive after sometimes it was inducing what is called chalking. In some light it can deteriorate the paint because in the paint you have also some organic component. And in 1921 there was a first report that TiO2 can interact with light and can induce in this particular case a reduction of TiO2. And you can find very accurate studies about the photoactivity of titanium dioxide in 1930s and 40s. So it's nothing new, let's say. It's quite well known. And the first report of the possible production of hydrogen from water electrolysis is from 1972 and coming back to the talk I gave yesterday is an interesting paper to read because it was less than two pages long. Five references. It is now highly cited. I think such a paper today will not go through the pre-review process because almost nothing is written in this paper. They simply said we suggested what can be decomposed by visible light into oxygen and hydrogen without application of any external voltage. So it was very interesting paper but it's very simple. But this is the idea. So the idea is not new. And after 50 years we are still debating what can be done and why it is not so efficiently done. Well, I was telling you the four requirements. And this is TiO2, TiO2 has two structures who tied or annotate. In both the band gaps, so the excitation, is between 3 and 3.2 electron volts. And if you look at the solar spectrum you realize that the number of visible light photons in the coming from the sun is just a very small fraction. So with this material we can only use this very little amount of photons which are able to excite electrons from the valence band to the conduction band. This is the first drawback. It is the first problem. Of course you can say, well, let's move out from TiO2. Let's take another semiconductor. And of course there are tables and theoreticians have done a lot of work in this field. You can compute or can you measure the properties of the various semiconductors in one of the second requirements. TiO2 is a good band gap which is a bit too large. It has a good position of the conduction band which is above the water reduction potential or of the valence band which is below the oxygen, oxidation potential. But of course there are other semiconductors with smaller band gaps so they absorb more visible light. But for instance the position of the conduction band is too low and the water condition of the valence band is too high. And you can also have materials which on paper are perfect. They have the right band gap and the right position of the valence band and conduction band. So why they are not using that? Well, first of all, you have to measure the real photoefficiency. And if you measure the real photoefficiency which means how many molecules of hydrogen we are producing per photon and how much photocurrent we are generating with irradiation. Well, for instance, you see TiO2 is here very low efficiency for the reasons that I mentioned to you. You may have better materials but you have, it's not enough to have the right position of the conduction band and valence band and band gap, you have very combination and the recombination reduces severely the efficiency and recombination, as I told you, there was a very beautiful lecture yesterday by Giulio Czerullo, so essentially it occurs in two ways. You can either recombine electrons and also generate photons as a mission of photons or you just have non-radiative recombination and you just increase the vibration and moles of your lattice. But even if you have the right material with the right band gap and the low recombination, is that solved the problem? There are also materials which are stable in working conditions which means liquids at various pH. So you need a material which does not dissolve when the pH becomes too acid or too basic. So this is the stability of the semiconductor is a very important issue. And that's why TiO2 is so much used because it's stable, it's non-toxic, it's basically it has a number of properties. And so people started to say, okay, let's follow another way. Let's take materials which are, I mean, not ideal but a good starting point and modify them, for instance, by doping. So let's see what can you do with doping. So the idea of doping, doping means when you have a material and you add a natural atom, whatever, it can be a metal, it can be a non-metal and this atom can enter either in the lattice replacing one of the existing atoms or can go in interstitial positions that depends very much on the synthesis and it's not the same, but of course this is just one possible thing. And what happens when you dope your material? Okay, here is a very important conceptual illustration. This is the starting material. You have a valence band, you have a conduction band and you have a given absorption of light, if you are below the threshold and then you have a suction. Now you introduce a dopant. The dopant can introduce a level in the band gap and then you can excite from this state to the conduction band and this can be done in visible light, much more efficient or you can introduce an empty level in the band gap and you can excite from here to here. So these are all phenomena which are absent in the pristine material and if you have this kind of situation you start to see that the absorption occurs at lower energy so you start to have to capture photons of visible light. There is another possibility where by doping the material and changing the electronic structure you just shift, you notice that this band is shift to higher energy so you move the entire band and you reduce the band gap and you have simply a shift of the entire absorption. Let me anticipate that this is really what we would like to have to modify the valence band and move the entire band. Unfortunately, this is what happens in most cases and I will be more specific about that. So there is another problem and this is a typical if you want a problem but I think it also has a lot of consequences which has to do with the localization, we generate an electron and a hole. Now, this is a picture which shows there is an electron in the conduction band so you have excited your electron the electron can be delocalized what does it mean, it belongs to the entire lattice it is these yellow signs which are basically spread over all atoms or it can be localized what does it mean it is sitting on a single ion and you see that there is a distortion of a lattice around it well when you have this localization you gain energy we gain energy and this is called a polaron it is a polaronic state the lattice distorts in order to trap the electron and localize it well, you realize that two situations are quite different here is an electron in a specific site here is an electron which is spread over the entire material and in terms of conductivity this is really quite a lot of consequences the same occurs for the hole you can generate a hole so you can form a single hole and you see this is the typical shape of a p orbital of an oxygen atom in the valence band which can be localized or can be delocalized but again the localization of a system and to the formation of a polaron now the nature the localized or delocalized nature of electrons is crucial in this kind of processes and this brings me to the topic of theory I will not speak of theory of these systems just a few general very general concepts of course nowadays most of electronic structure calculations are based on what is called density functional theory but the only message I want to give to an audience which I guess probably is mostly of experimentalist is that there are many variants of density functional theory they are not all the same and there is a hierarchy of accuracy in the methods that you are using and this problem of localization of delocalization critically depends on the level of theory that you are using to describe your material general most classical approaches are the so-called LDA or GGA functionals but if you really want to describe properly this phenomena and the localization of electrons and holes you have to go to higher levels in particular to what are called the hybrid functionals which are more or less at this level in this ladder now let me give you an example of what I am trying to describe this is again a case of TiU2 this is absorption band of TiU2 which as we have seen start to absorb above 3V if you dope with metal with transition metal iron tungsten chromium or vanadium you have to start to absorb higher wavelength which means lower energy photons now why is that if you do a calculation with an LDA or GGA functionals so you take for instance chromium doped TiU2 which means you put a chromium instead of a titanium in the lattice what happens? you have a valence band you have a conduction band and you have a new state which are due to this chromium doped if you look at this picture it looks like you have a small band which would be good actually which is crossed by the Fermi level but this picture is incorrect and this would lead to a delocalize nature of electrons why in reality the electrons are strongly localized and we have strong localization these levels have different positions in the band gap for instance we are very close to the valence band and the fact that you have localized electrons also is detrimental for the photo activity because these are very good trapping sites and so you increase recombination rates so the localization is negative for the properties of the material but only the right theory can describe proper reviews and this is another example because what I show you was delping with a transition metal in 2001 there has been an explosion of interest towards doping TIO2 with non-metal atoms like nitrogen and this was stimulated by a paper published in Science by Azai and co-workers the paper is now more than 9000 citations what they did they were talking of environmental photocatalysis not of fewer production but what they were showing is the following if you take TIO2 either pure TIO2 or nitrogen under UV light not visible light UV photons well it has a high efficiency in degradating pollutants however if you take visible light the normal TIO2 is non-active basically there is no conversion why the nitrogen doped TIO2 is very active because you start to saw photon of visible light beautiful they also provided a theoretical explanation of this and the explanation was based at that time to non-state of the art calculations but basically showing that you had this effect broadening of a band and the reduction of a band gap which would be fantastic that was the prediction well first of all let me mention that nitrogen doped TIO2 had been studied in 1986 by Sato but nobody realized that and he published exactly the same results 15 years before and this is the paper by Azayin Science going back to the distortions of modern science the paper of Sato never got cited until 2000 when this paper appeared somebody rediscovered that paper and that paper got cited 15 years after it was published but is essentially the same that was reported in the paper by Sato now why there is a what is the problem here let me open another issue this is TIO2 again the band gap is about 3.3 ev oxide semiconductors are never perfect you always have defects defects for instance vacancies, auction vacancies so they are very hard to be prepared in a fully stoichiometric way so what happens if you remove an oxygen atom from TIO2 the auction 2 minus remove an oxygen and the two electrons remains in the material and they are located in states which are close to the conduction band here more or less so high in the gap why this is relevant when you dope the material because you dope with nitrogen and nitrogen introduces a state which is close to the valence band so low in the gap and you have auction vacancies which introduce states high in the gap close to the conduction band so what happens naturally these electrons is transferred to this state and you form a new state which is doubly occupied notice that this is paramagnetic single electron this is diamagnetic why this is important ok, first of all the first message is when you dope a material there is a huge field you never have a single dope which introduces a single level there is a lot of possible interactions with others phenomena that occur in the same material in this case nitrogen doping for instance strongly favors the formation of auction vacancies because it lowers the cost of species and this was clearly demonstrated sometime ago with my colleague Elio Jamello in experimentalist in Torino because if you irradiate with samples with visible light you have diamagnetic centers because n with one extra electron is diamagnetic you excite electrons into the conduction band these electrons become active and you generate paramagnetic states which can be detected by APR now this study was very important because it demonstrated quite clearly that these states are completely localized are not delocalized contrary to the picture that was presented in science and since then we did a lot of systematic work on the various dopans that you can have in TiO2, boron carbon nitrogen fluorine and all the dopans introduce localized states so you may have a very stable state which are in the middle of the gap you reduce the absorption that is beautiful from the point of view of the absorption properties that is not so nice from the point of view of the recombination problems this doesn't mean that doping is useless there is a lot of work which is still being done on doping and codoping but of course let's move to another way of improving our activity hetero junctions Julio Czerulo has been talking yesterday about junction combining graphene with 2D materials and so on the idea is the same you can do it with semiconductors again is not a new idea I'm not sure this is the first paper Michael Grezzo proposed this in 1984 but the idea is very simple, you take two materials now, two semiconductors put them together and of course the idea is the following you excite one semiconductor you generate holes and electrons the electrons are where since you are in contact with another semiconductor, the electrons can move to this side on the other end you have this hole here which basically is filled and you generate and the hole moves in this direction so the electron moves on the left the hole moves on the right and you separate electrons and holes and separating the electrons and holes you avoid recombination this is a beautiful idea and of course it works partly there are various kind of hetero junctions it depends on the position of the levels but that is more technical and the idea which is even more sophisticated and which partly go back to the natural photosynthesis is to you take two semiconductors with different position of the band gaps but you put in between a chemical redox system what does it mean a chemical redox system you have one material where you basically generate the electrons and the electrons are consumed by these redox and you generate holes and the holes are used for your reaction on one side on the other side you generate the holes which are consumed by the redox couple and the electrons are used for the reaction on the opposite side again is engineering the system in such a way that you keep as far as possible electrons and holes to avoid recombination this is called Zetoski and so this is the general frame and now depending on how much time is left I will describe some practical results taken from our own work also to show you how things go when you go from theory to praxis I will discuss the case of basically mixing semi conducting or insulating like Syria with zirconia and zinc oxide there is an experimental part which is not my part I will mention that it is done again in the group of Edo Giammello but ok so in the first part I will show what happens if you mix serum dioxide with zirconia in the second part if you mix serum oxide with zinc oxide so we have the same component mixed with two different oxides notice that this is a wide gap zirconia is a gap of 5.5 EV zinc oxide is a wide gap semiconductor 3.4V so we are completely inactive in visible light ok so these are basically with two compounds but the preparation of the first compound is done by solgel solgel is a chemical way of producing new materials and of course you start the synthesis and you don't know exactly what you obtain and in order to know what you obtain you have to do a number of characterizations and here what happens this is an extradi fraction pattern it shows very clearly that in this synthesis serum is entering as a dopant in zirconium dioxide so it is diluted as a dopant you don't have segregation of different materials well you have produced a new material and now the first thing he wants to do is to see what is the activity or what is the activity in under visible light as I told you prist in pure zirconium dioxide is a gap of 5 EV will never absorb visible light photons however if you dope with serium this is the absorption of pure zirconium no absorption in visible light if you have serium doping 1, 2, 5% you start to absorb light in the visible light region ok, that's already interesting it doesn't say much you have to see what is visible light doing and you can do this again using electron spin resonance because using electron spin resonance to make the story short you take the spectrum the different spectrum before and after irradiation and you see that under visible light visible light not UV light, you generate holes and electrons so clearly you are exciting electrons or valence band to the conduction band of the material not only this but if you now look at what happens at the surface of the nanoparticle you can react molecules like oxygen electrons are trapped by oxygen you form O2- and O2- is again can be seen in electron spin resonance which means that the electrons and holes are generated in the nanoparticles they migrate and they reach the surface and at the surface they can react both the electrons and also the holes through a more complicated mechanism but you can detect the formation of holes so the message here is yes you take a material which has no absorption visible light and it becomes active invisible light and the electrons and holes are generated and reach the surface now what is the mechanism we are not yet completely sure about what can be the mechanism what theory tells you that we do calculations is that yes, you have a wide gap insulator but the Syrian dopant introduces new states in the middle of the gap and these new states can act to some extent as in intermediate positions where you can have double excitations you can excite first to these levels and then from these levels to the conduction bed it is not so easy now I don't want to open how to compute excitations in solids which is not a trivial task but here we did it for the people of the experts in the audience using the so-called transition charge transition levels but finally we compute the transitions which are 2.5 and 3.1 which are compatible with visible light absorption in particular if you take into account that you have an overestimate of a bang gap of about 15 percent so the message is of this first part here doping in purity atoms Syrian replacing zirconium in new states in the gap and a material which has no visible light activity become active in visible light now let's take the second example which is again Syrian oxide mixed with zinc oxide the synthesis is again solgel so it is basically the same you start from precursors and so on interestingly enough the final compound that you get is completely different there is no longer serium diluted into zinc oxide but very clearly the synthesis has produced small aggregates of seriodioxide so nanoparticles of seriodioxide on nanoparticles of zinc oxide so there is a natural junction and this depends on the synthesis and is very difficult to know a priori what you are going to get but this is quite clear there are a number of measures showing this formation of two separate phases seriodioxide and zinc oxide however interesting enough also this material becomes slightly active in visible light in sort visible light more than pristine material but more important under visible light again you can follow the generation of species, holes and in this case zinc plus ions, electrons in the conduction bed again using visible light so zinc oxide has no absorption in the visible by mixing or creating a natural junction you make the material active in visible light and why again here theory can produce some answer here what we did we constructed a model of the junction which is not the trivial thing because when you have two materials of course you have strain you must have lattice constants of the two phases which match together nobody really knows what is at the interface how the interface is done and so you have to create a model and hope it is close to reality because it's not so obvious so we started this hetero junction and we computed the lowest excitation the lowest excitation turns out to be much lower than in the two separate materials and the reason is that now you excite from one component, from zinc oxide from the valence band where you generate an O minus you excite into the other component and you generate a serium 3 plus at the interface and this excitation starts at the interface at much lower energy than in the bulk materials when they are taken separately ok, again this shows that these electrons and ores in the real material they reach the surface they interact with molecules on the surface so they produce photo catalytic processes and in fact this material has been shown to be very active in the degradation of pollutants under visible light ok, this is basically the summary or basically what I wanted to show you that you can take you can modify semiconductors the what you get is largely determined by the synthetic procedure and it's very difficult to know a priori what is going to happen but I show two examples where you can end up with a real doping case I think still there is a lot of work to be done in this field which however is quite exciting and I would like to thank my co-workers and in particular my experimental co-workers for the part of the talk that I've shown to you thank you very much for your attention


I know that's difficult to pronounce. I usually go just with the first name, Slava. I started to use Linux when I was still in high school and since then I've worked in different industries, aviation, a bit of a telecommunication, metal industry. And that allowed me to contribute to various open source projects. Linux kernel, trusted firmware, ARM bootloader, and also Yocta project. And now I contributed the overlay FS classes to open embedded core and I try to maintain them. So before we start what the overlay FS is and what it helps us to do, we better understand the problem we are trying to fix here. And then we go into details how overlay FS works and how we can use it in Yocta. So imagine your embedded device. So what you usually do when you design it, you usually have some partition layout over there. It can be just the whole partition, the whole root FS takes up the whole space or you can have a root FS partition and then some application data partition. That's just an example. Usually in those two cases, you would have the update mechanism like OS tree or SW update or I also saw some devices that just use a homegrown update mechanism based on Squash FS images. Or we had heard a lot of talks during the week about AB update scheme where you have one root FS partition currently active and the other is on standby. You could also have the same layout and some application data partition. In that case, we saw some, we heard some talks during the week about a software update, rogue, a Mender, which are used in that configuration. That could be others. That's just an example. That also could be other partition layouts.  The purpose of the device is that it runs something and it's supposed to do something. And it's not always that you develop your application from scratch. Sometimes you develop a next generation of your device, so the application is already there. And there are also some services which your device provides, for example, like DNS service or something else. And your application or service, it always has a writable access to either root FS or some configurable partition. In a lot of cases, it just writes the root FS and that could be a problem with the AB update scheme because when you update, you update the whole root FS and the whole user data is gone. So what can we do here? The simple case and the best case actually is that you make your application configurable where it writes to. So it doesn't write to the root FS but it just writes to your data partition or TMP FS if you don't care about the data. But in a lot of cases, it's really not possible to change the application because it's a huge legacy beast or it requires a lot of time and effort, a lot of hard-coded parts in the code. So what can we do here then? The simple case, we can create a sim link which will point then either to a TMP FS or to the application data partition. That works for simple cases. If it's just one or two sim links, that can be manageable. What if there are like dozen places your application writes to? Then it becomes more difficult. The other approach could be a bind mount. So you bind mount the directory which points again either to TMP FS or to your data partition and bind and mount back to the root FS. That also solves the problem. But in some cases and a lot of cases, the path your application writes to already has some predefined configuration and you want your application to keep that configuration. In that case, all the FS can be handy. What it does, I explained in a few slides, then your data which comes from the root FS is available and it can write but the writing will be redirected either to application data or TMP FS. While the application still thinks it writes to the root FS. So what over the FS is? So that's the excerpt from the Wikipedia. When I first read it, it's an implementation of a union mount file system. Like, okay, what is a union mount? And I went further, so union mount is a combination of multiple directories which appear as one. So how does it look like? Imagine you have a directory one with files one and two and also five and directory two with files three and five. When you mount an overlay, you look at it like from the top. So you would see all files present as in one directory while underneath there are two different directories. Before I go with an example, how to achieve that in future monology. So in overlay FS, the lower layer or lower directory tree is the one that appears below. So in this case, that would be directory one here would be considered for overlay FS as a lower layer. It can be read only, can be read write two but the writing will not go there. The upper layer or upper directory is a directory which appears on top of that. So that's directory two. These can be writable. So, and that's what's interesting in our case if you want to redirect the writings of our application to another partition. The limitation for directory two that it has to support extended system attributes. So in that case that NFS is actually not supported because it does not support it. And then we have the mounted overlay or merged layer, so to say that will be this one. Another interesting term is writeouts or a back object. I will show it later how it's used. This is a file directory which is a marked on the upper layer as removed because we have a transparency that application can do whatever it wants in overlay. It can read, write and also can remove. And those modifications are stored on the upper layer. Now an example, that's our directory one with two files or three files and directory two. You see there's file five which is present on both directories and the content is different. So that's a file from directory one, file from directory two. So now the command to mount an overlay looks like that. You mount the file system type overlay and then you mount a special type overlay. So those are different things. That's the thing you mount that's a file system type. This is where you mount to directory three. And the whole configuration which we just discussed lower layer, upper layer that goes in the options. So lower layer would be directory one, lower tier, upper tier would be directory two. And then there's a special argument called work tier. You have to specify that in order for overlay to work. The limitation here that the work tier has to be on the same file system where directory two is. I just duplicated the mount command again just to see upper and lower tier. And that's how directory three would look like after we mounted. It would have all the file files and we see that content of file file is gonna be the one from the upper layer. Now that's a removal case. If we remove file from the overlay, we take for example file one and we see that it is still present on the lower layer. So lower layer is not touch here. But on the directory two, a special device is created with the major and minor number zeros. It's a special character device. And this is the write out. That's how it marked on the upper layer that the file is removed from an overlay. So you see here in the overlay, it's not displayed anymore. This is a bit more difficult example. Now we unmount the overlay and create a few sub-directories to see how the directories are handled. We create sub-director one and two in the lower layer and sub-director two in the upper layer. And if we mount it again, we see that they are present on the mounted overlay. But we have here two sub-directories. So right now they're empty. But if they had some files, the content of sub-directory two would be merged too. Now this is an important thing to note. I will mention it also later. If you wanna do any modifications on the layers of the overlay, it has to be done offline. So overlay FS does not support changes when the overlay is mounted. Well, it says that official documentation says that the behavior is undefined when you do that. It will not cause a crash. But if you want to have some modifications, you have to first unmount an overlay. And that's another test. We remove the sub-director one from mounted overlay and then we create it again. Please ignore this for now. So if we take a look at the directory two, that's an upper layer, with the command getfattro, this one with the parameter dash m dash, this should list all the extended attributes on the file system. So that's what we wanna do. That lists only the attributes. It does not list the values of those attributes. And we remove the sub-directory one and you see it got the attribute pack. That means if we now unmount an overlay and create anything in sub-directory one on the lower layer, it will not be displayed on the overlay. Because it was already removed from the overlay. So whatever is displayed in sub-directory one would be from the upper layer. So lower layer in this case is hidden. Now this test again, if we do that offline, we create that file. And this file on the overlay, the sub-directory two gets the attribute origin. That means the files from the lower layer will not be hidden. You see them here on the mounted overlay. Those attributes, I think they have some values. You can see them, but that's implementation-specific. If you add minus D option to dump the values of those extended attributes to see some value. But that's not really interesting for now to see how it's implemented. Yeah, now what do you need to do in the kernel? That's a simple. In your DevConfig and the Yocto, you just define oralFS yes. Or if you use the Linux Yocto, you can also use kernel features, which would be features oralFS and just oralFS SCC. That does exactly the same thing. Those are special features or oralFS. For the use case, I'm describing here, they're not really interesting. Even more, they should stay disabled. Because remember our use case when we wanna update the entire file system, AB update. And imagine that our application got a new config file in the mounted overlay. So that config file obviously goes under the lower layer when the file system is updated. And the upper layer would be our data partition. So the tricky part here is that this is allowed when all those features are off.  It's either you disable them in the kernel configuration or you provide mount options to explicitly mount an overlay with all of them are off. And this is, there was actually a bug in the kernel, regardless what was written in the documentation, it was still not possible to get those files after you update the system. They were not visible. That was fixed in kernel 5.15. The patch was accepted upstream. So if you use an older kernel, I think there were three patches. And you have to backport it to an older kernel. So that is actually excerpt from the documentation. Again, that's what I said. So if you do online modifications to the layer, their behavior is undefined. You might see that might not, it will not result in a crash or deadlock. But I wouldn't go into the undefined area here. Right, and how do we use it in Yocto? There are several ways. Depends on your system configuration. You have possibility to use it in InutrameFS. There's a recipe Volatile Binds and their classes OverlayFS and OverlayFS ETC. For the InutrameFS, the recipe is located in open-abended core, recipe score, init-rd-scripts. You have to include the package, InutrameFS module over the root. And then when you boot such kind of system, you have to provide the kernel argument, root Rw, which should point to your data partition. And that would mount an Overlay for you. It does not require image feature to be the only, but I think if you're using InutrameFS, most likely it is. The Volatile Binds. The recipe has been there all along and the name is actually a bit misleading because it doesn't mention any overlay. So what it does, you have to include, not include, you have to provide the BB append. And in your layer, you would just extend Volatile Binds variable with two parameters and the new line separator. That would be your upper layer, that would be your lower layer and at the same time, that would be amount point. So if you imagine the picture I showed before, that would be the director one, that would be director two and that at the same time would be merged overlay. So this you will still see as amounted, as a content of unamounted overlay, merged with the changes that your application writes and you're still your application writes back to the same location. If you use system D, Volatile Binds is already included implicitly in your image. And basically it's a BB append. So it works on a layer basis. If you enable a layer in your configuration, then mount points are created or if you disable it, not created. But there's a tricky part. So like I said, the recipe is called Volatile Binds. So originally it created only bind mounts. So how it works now, it tries to mount an overlay and if it's not successful, in case, I don't know, overlay is not enabled in the kernel. One example, then it rolls back to the null behavior. It copies everything from the original directory to the upper layer. It's not gonna be upper layer, it's gonna be bind mounted later back. That's the original behavior and you still can use it. But the downside, the default configuration works only when your root of S is read only. So the template for the system de-unit or for the implementation checks that file system is read only. If it's not, it just skips it. And yeah, that's just for me. You have to know it exists. So the name doesn't say anything, how to use it. And it's not really obvious when you wanna achieve something like that. Now regarding all the FS class. So I contributed, I think at the same time, like when Volatile Binds was extended with the overlay FS support, what you need to do is a bit more tricky, but it's more generic at the same time. In your recipe, in your application, you inherit the overlay FS class and you specify overlay FS writable path with the key. And this would be the list of your directories you want to mount as an overlay. Now, in your machine configuration, you would have overlay FS mount point with the same key. And this would be the mount point to your data partition. So why is it with the keys? So because you might have several overlays, you might have one data partition, you might have another overlay which points to TMP FS. For example, for the data, you don't care, but you still want to write your application to be transparent, to have transparent writing, to try to root FS. And then in your distro configuration, you just add the distro feature overlay FS. So what it does behind the scenes, it has a lot of QHX that you have this mount point already available, that you properly, if you, for example, define only this, but not this, you will get an error. There are a couple of unit tests already covered in open embedded core to make sure that works correctly. And it works on the recipe basis. So if you do not include your application recipe, which uses that class, then the overlay mount points will simply not be created. It works for system D only. I did not implement it for other init managers. And it works regardless if the lower layer is read only or read write. So that way you can have several testable configuration and make sure your overlays are always there. Another class is overlay FS EDC. I saw a lot of people actually ask for that feature because the possibility of mounted overlays on application basis is good, but you might have some services which want to write to EDC. And that is a bit tricky part because the first thing, which is done when the system boosts, it starts the system D or your init manager, and that takes ownership of the EDC. You cannot do anything after that. You cannot remount the EDC. What you need to do in your image recipe is add a feature over the FS EDC. And then in the machine configuration, you specify the mount point and the device. This is needed, of course, because it's one of the first things which is done after boot to mount your data partition. Most likely that's going to match if you use overlay FS class with those path going to match with that. And what's happening behind the scene, there's a template script which runs first thing after boot instead of your init manager. Then performs the mounting and remount EDC for the overlay. And then hands over back to your original init manager. Yeah, this is useful, but you also have to keep in mind. So if you do debugging, you need to make sure and keep in mind that all writes go to overlay and if you want to restore something, you could just unmount your overlays and restore the content. With EDC is not really possible. I recently contributed a fix that the original EDC content is also available for read-only purposes if you want to restore something. Now regarding more debugging techniques and useful utilities, there's this overlay effects prox repository on the GitHub, which provides FS check overlay utility. There's also a recipe for that in meta open embedded. I didn't work with that extensively. I think it checks the validity of the upper layer that all the attributes are written correctly. There is another repository which is called overlay FS tools. It provides more interesting utilities which you can use. And the recipe is also available on the meta open embedded. That's again a comment from me because you see the name seems to be the same tools or prox and actually the make file is almost the same. It just compiles in the same way. I try to contact the maintainers but they don't really respond. Maybe it makes sense to combine both projects and just have one tools which provide all of them. If you know how to do that, please feel free to contact me. Yeah, and there's another one which is called XFS tests that the name actually doesn't say that it's overlay FS related but it's hosted on the kernel Git repository. What it provides is provide a lot of file system tests. So it's a big QA test suite. If you find a bug in overlay FS, you would use that recipe and meta open embedded and that test suite has a lot of overlay FS related unit tests, so to say and which you could use if you find a bug in the kernel in the overlay FS implementation to check that everything still matches with the expected behavior. If you had a new feature, of course you would need to extend the test too and the patches and bug fixes should be sent to that mailing list address. Yeah, those are the articles and official documentation and those are two main maintainers of overlay FS. Yeah, I think that was it from me. Thank you very much. If you have any questions, maybe I missed something, forgot something. I think that's something that overlay FS does internally. So the question was what work directory, what is work directory for? Whenever I always check the contents, it was empty. So probably it's needed at runtime. So I don't have insights what is happening behind the scenes. Yeah, the source code is in Linux kernel, yeah. I'm pretty sure when the system D starts, it uses a lot of an ETC and you cannot remount it anymore. I didn't try, but I think that might fail. The question was what's special about ETC? Yep. I guess that counts as a modification to completely replace it. Yeah, so the question is how is ETC affected after the update, correct? So when you do the A-B update scheme, you update a standby partition and then after reboot, the lower layer basically is changed offline. It's not online. And whatever files you had on the upper layer, of course take precedence that will be your modified configuration. If you need to change something and take it from the new update, that has to be done manually and handled manually with some update hooks. For example, no, no. Because the changes are offline, you reboot the system to a new standby partition. So the question is, can you modify the upper directory? Online or offline? So offline, again, no problem, online. So like I said, behavior is undefined. You can try. Yeah, the question is back. As an upper layer. Yeah. So the question is, can you export NFS directory and use it as an upper layer, right? I think so, yeah. That's a good question. I haven't tried that. So that was not my use case because we are on an embedded device. I didn't need to export NFS here. I'll try it then. Yeah. Yeah, one more question. So when you, yeah. It's not correctly said on the or before the file system. And so that we need to perform something. I'm not sure I understood the question. So when you use extended features of all RFS, would that be problematic in that case? You mean that's a good question. So is there any mechanism for the overlay to be mounted properly? Right? I think there was a fix recently for the overlay FACTC class that now all the features switched off during mounting that I could contribute the same for the overlay FACTS class, but for the ETC, that's the case. So they have switched off already. Yeah, one more question. So is that a question or just comment, comment? Okay. So for me personally, the message is if you can modify your application, that would be the easiest way. If you can't, simply combine mounts. Otherwise you should use overlay FACTS, but you see there are a lot of tricky parts here and a lot of details you have to keep in mind. Yeah, so no more questions. Thank you very much. Thank you.


Bonjour tout le monde. Hello everyone. Today I want to start by highlighting some good news. Last night, Health Canada announced that it has authorized the first serological test for COVID-19 antibodies. This is a critical step for the work of the COVID-19 Immunity Task Force, which now has a safe and approved test that can detect antibodies specific to COVID-19 in an individual's blood. These tests will help us better understand immunity against the virus and how it spreads so we can keep Canadians safe and healthy. Last night, Health Canada announced that it has authorized the first serological test for COVID-19 antibodies. This is a critical step for the work of the COVID-19 Immunity Task Force, which now has a safe and approved test that can detect antibodies specific to COVID-19 in an individual's blood. This is an important step to better understand the mechanisms of immunization against the virus and how it spreads. This will help us ensure the health and safety of Canadians. I now want to turn to what we're doing to help employers keep their employees. Over the past few weeks, our government has unveiled a number of measures to help businesses stay afloat during the crisis. We want to make sure that as many Canadians as possible can keep getting their paycheck now and have a job to come back to once the pandemic is behind us. Because that day will come, and when it does, Canada needs to be ready. Our government has been laying the groundwork for our economic recovery, and we know that key to our collective success is maintaining the connection between employer and employee. So, to help businesses of all sizes keep people on the payroll, we launched the Canada Emergency Wage Subsidy. We also introduced the Canada Emergency Business Account to support those struggling with cash flow. These measures are making a real difference in people's lives. So far, more than half a million small businesses have received a loan through the SEBA, and over 120,000 employers have been approved to receive the Canada Emergency Wage Subsidy for almost 2 million workers. We also announced more targeted support for regional businesses, including those operating in the tourism sector and seasonal industries. We created a nearly $1 billion regional relief and recovery fund to ensure that they're also getting the support they need during this time. The funding will flow through the six regional development agencies with a portion dedicated to the Community Futures Network to assist businesses in rural and remote regions. Today, we're releasing more details on how that money will be split between the Atlantic Canada Opportunities Agency, Canada Economic Development for Quebec Regions, FEDDEV Ontario, FEDNOR, Western Economic Diversification Canada, and CANNOR. And here's the bottom line. These organizations understand the economic realities and specific challenges facing both your region and your business. They can help you with your most pressing needs, whether it's covering costs or keeping your employees. So if you're struggling but did not qualify for other programs like the Wage Subsidy or the Emergency Business Account, give them a call. They're there for you. A few weeks ago, we created the regional relief and recovery fund that has an envelope of nearly $1 billion to help small employers in rural regions or those operating in the tourism sector or seasonal industries. The funds will be generated by the six regional development agencies. A part of the funding will also be dedicated to the Community Futures Network to support businesses in rural and remote regions. Today, we're releasing more details on the distribution of funds between different regions. And here's what you need to remember. Whether it's FEDDEV Ontario, DECK, or the Community Futures Network, these entities understand the economic realities and specific challenges facing your region and your business. They can help you with your most urgent needs, whether it's liquidity problems or keeping your employees. So give them a call. They're there for you. From the outset, our government has been focused on getting people the help they need as quickly as possible. We announced support not just for businesses and their employees, but for different groups of people who've been hit especially hard by the pandemic. A few weeks ago, we launched the Canada Emergency Student Benefit as part of our $9 billion plan to help young people get through the next few months. And today, I can confirm that students and recent graduates will be able to apply for this benefit starting Friday. To prepare for that, if you haven't already signed up for the My Account on the CRA website, it's worth doing this now to make the next steps go even quicker. I also have news for students and new graduates this morning. From Friday, you will be able to submit a request to receive the Canada Emergency Student Benefit. This new proposal is part of our $9 billion plan to help you during the pandemic. Because of COVID-19, there's not so much work for students this summer. And you need to work during the next few months to pay your school fees or your daily expenses for the coming year. The Canada Emergency Student Benefit will therefore be there to help you. You will be able to submit a request starting Friday, but in the meantime, it's worth going to the agency's website to sign up for my account if it's not already done. It will further accelerate the process. I finish this morning by reminding everyone to continue to follow the recommendations of public health experts. We hear a lot about the gradual reopening of the economy these days. I know we all hate it, but we must remain vigilant. So, continue to stay at home as much as possible. And don't forget to keep your distance when you leave. And together, we will get there. Thank you.


And the International Monetary Fund has said Nigeria will likely depend on overdrafts from the CBN to fund its proposed 2.55 trillion Naira petrol subsidy bill, and this is following the federal government's plan to extend the fuel subsidy regime by 18 months. The IMF said these in its Nigeria selected issues papers report. The report was prepared by a staffed team of the fund as background documentation for its periodic consultation with Nigeria. According to the report, fuel subsidy negatively affects the country's fiscal position, increasing fiscal deficits.


Good morning to each and every one of you. It's a favorite village boy, Mr. Ghana baby right here in my favorite city In the entire world you all know it. Can you guess it? Kigali, but I mean being in Kigali. I just want to say thank you so much For no more hotels for hosted me. It's been absolutely amazing spending a few nights in here I'm not here for so long actually came here for three good days And I'm going to Goma at this very moment last night I posted a picture on Instagram just telling people that I'm in Kigali because I know that I'm living the next morning You know, but as soon as I posted that I stepped out of my room just to come and have dinner And I found out this young man sitting down just waiting for me. I have to go right now I said I have to meet you. I moved here two months ago because I saw your video last year From America and you got to see my IG post so you have to come and see it. Yes, and what if I didn't come up? It's not safe for me to share my locations these days I know on my way to meet the man myth and let you oh my boy look at that Jeez, yeah pleasure man. It's a pleasure.  He came here with his mom Yeah, I just have to share this which you all may be their story might inspire you to also move to Kigali someday So come with me as I go speak to this family that move all the way from America to Rwanda Kigali. I don't know even if I have to introduce myself because I love telling people that I'm the one and only I know your village boy from Ghana but since you know my name is Wotamaya already I don't think I don't need further introduction Legendary Wotamaya Mr. Ghana baby Mr. Ghana baby Wow, you know the food man Yes, yeah What brought you to Rwanda? Honestly Something wanting something different. I always wanted to live abroad and Last year presented the best opportunity to make that happen and I was actually happened I actually saw a video by a youtuber named Wotamaya Who was here in the Rwanda? Oh wow and seeing that video definitely inspired me to Come here because I know you were looking at wanting to relocate to Ghana. Oh, you wanted to go to Ghana She was looking at relocating to Ghana I was looking at Ghana and Tanzania and Rwanda and then I saw you here doing a video and See, I want to say something. Yeah, you said you wanted to go abroad Yeah, see when it comes to Africans Africa is not abroad for us to the standard an African living in Ghana I don't even want to like, okay. Why would I if I want to go abroad? Why should Rwanda come in mind, right? We chose Africa. Yes, I saw abroad. Yes, Africans don't want to choose Africa as abroad You know, I want to tell you something your inspiration to so many Africans living on the continent not Africans even abroad right It's a pleasure to meet you. I was so inspired on a metro yesterday trust I think I will post it on Instagram today Thanks for taking that step because I should be out of Rwanda this morning But because of you have to be here so that you be able to inspire so many young Africans living in Africa and living abroad First of all, I want to know yet before moving to Africa, right? What was your perception that you have for the continent before coming? I had an excellent perception because my mother she had gone to Ghana back in the early 1990s So she really taught me a lot about Africa in Ghana from a young age So I didn't have that the normal perception that most black Americans have of Africa What is that no more perception that black Americans have about it's backwards. It's it's it's Africans are dumb. They're starving wild Untamed wild right not not civilized Just it's just all negativity. That's not true, right? It's not true, and I never believed it was true Even as a child. I never believed it. I never because I said if I am from this country this this Continent and I'm not like that My family's not like that. How is it that I'm not like that? But everybody in Africa is so I never believed I knew they were lying to me I knew as a child that it was a lie, and I came to find out for myself Went to Ghana in the 90s I had a pen pal at 15 years old and you wrote until I was 20 something and I lost contact with him Oh, and I found him 20 years afterwards, and I said it's meant for me to go So I came to Ghana and loved it. I Was at home Soon as I got the plane I was like why why do I feel like I've been here before? Oh, I felt like I had been in Ghana all my life. I felt at home. I felt relaxed I felt at peace. I've never felt that in the United States Not like I felt here. I'm like I'm at home I remember being in the plane and crossing over and I went I'm at home on the plane I'm home, and I just loved it every since I went back and told people you know like that to Ghana Everybody looks like people, you know in the United States.  I'm always on guard How long did they stay in Ghana the first time six weeks and you went back again? I went the next year for a couple of weeks Haven't been back since I just Until I came here. I knew I had to get out of America. I knew that I was like, I'm not safe here I'm not home. I'm not wanted there. I Knew that and I want I need to go where I'm from And I was just getting Building spiritual feelings. I knew we're saying yeah Yeah, it's not for you, but people like it and want to stay stay That's some people can live on the cage and feel comfortable. I don't It's like you put an animal in the cage. It's all they know you let them out. They'll just stay there. They won't move I Need to be free It's beautiful And I could talk about it forever The experience has been like I can't words cannot describe like the experience the people are absolutely beautiful like my mother was saying Very very hard-working. I've never seen a more hard-working people and I know it's not just limited to here in Vranda But I know it just in Africa in general You know in America we say that the Mexicans are the hardest-working people and with all due respect, you know to the Mexican You know community. I've never seen work done Like I've seen here before like This home if you see What the sort of materials and resources was used to even build this structure? You would be surprised that they came out with this result Because they do so much with so little and they don't complain and a very hard-working and it really inspired me So if I love it, it was like you're prepared so much before moving to Rwanda No Not really. I didn't make the decision until last year after seeing your video. I was at home During the lockdown. I was on furlough from my job. I wasn't working so just going through YouTube videos and I came across your video and The rest is history like I've never had a feeling in a moment like that because this country really reminds me of my home city in Oakland the hills is a Area of open Hills skyline Boulevard Mountain Mountain Boulevard It reminds me that it was like nostalgia. So like wow, I wonder where could I go? Where else could I go that would remind me of that but won't have that I won't have that same Feeling of being unwanted in America and Rwanda kind of did that for me. Is this safe in Rwanda? It's extremely safe from Rwanda. Women can walk by themselves outside at night. You don't have to do like this You don't have to carry a gun like you do in America and I shouldn't say this on camera But I'm going to the ATM many times at night at night beyond 9 p.m Coming with wads of money in my pocket and I've never even Had to worry about Watching over my back and I would never have been there. I did a video in Rwanda saying that Kikali's the key necessary in Africa It's extreme. Yeah, it's true. I was just lying to the people. I haven't been to other countries, but it's extremely clean It's extremely cleaner than America. Yeah, it's extremely. It's cleaner than America And I see no mama's people You can't trouble yeah, but so far so good You've been here for two months two months. What are you doing here at the moment? So right now I partnered with a local Rondon who I met prior to coming his name is Ben and we are starting a Video production company YouTube group and baby YouTube channel I should say and what we're going to do is merge the African community with the African American community And because I noticed a lot of you know people they come here that kind of They kind of stick to their community. Okay, but you know, we're one people. So what I want, you know us to do is kind of Showcase, you know our oneness and our unity The channel is created. However, there are no videos because it is brand brand new, but one of my is going to help Help but I'll see not secret. You've created it already. It's created. Alright, so we're going to link Can we link the link will be in the description description box? I would know it. It's by force. Yeah Thank you my listen We need to change the narratives of Africa and I've been saying that I cannot do that alone For me, I'm just a messenger. Is it like I'm just asking them the question and they are answering But if you want to know more about Rwanda if wanted because see being an African American Me being a Ghanaian and African American will relate to you more They're gonna relate to me. Right. So please check out the channel subscribe and believe me after watching these videos You might also make that move and move to Rwanda. Absolutely. It's exclusive Ronda. That's the name of the channel exclusive Rwanda Exclusive Ronda and it's X CLUS then I think and then I think visit Rwanda. You got ambassador right here You don't you don't need to look no feather. You got an ambassador who's gonna take Rwanda right to the world My brother But I mean I wanted to know is it affordable to leave you. I'm seeing your house It looked like a rich man living in it. Is it affordable to you? It's extremely affordable We're from California and say the Bay Area that would be in the millions several million four or five six million dollars Yes, and do you want to say what we? It wasn't you bought it. Oh, yeah, you bought it. Yeah, you bought it. We're not leaving Do you want to say I don't mind saying I don't mind saying Can we feel free? I'm in fact what we paid 170,000 US dollars six bedroom house six bedrooms and six bathrooms Not including is the bathroom in the back. So that's kind of like seven bedroom. I'm your seven bathroom. Wow. Yeah, Rwanda is definitely It's an option. You know, it's definitely an option. See people. I'm so tempted to see the six bedroom house But yeah, they'll take you on a tour exclusive videos. Go check out How much the inside of the $170,000 house, you know, I got so many Africa is watching us if you haven't missed it for them. What would that miss it be? Don't be so quick to want to leave Africa Africa has all you need if you're finding Stumbling blocks leaving the continent. Well, what is God saying to you? Stay here build it up Africa is on the is on the rise America is on a decline Europe is on a decline Australia is on a decline Africa is on the rise is a reason why Bill Gates and Warren Buffett and the CEO of Twitter are making their way out here Don't look any further than out to outside of Africa. Africa has all you need The richest country is right next door the Congo We just have to tap into the resources unite with each other and then Go from there Then what message do you have for Africans living in a diaspora your message and I'll come to mommy's message Got you Africans living in diaspora. Um At least come to visit if you don't want to move I mean, this is home. The earth is our home, but this is our base. At least come to visit once At least come to visit once and don't believe the narrative Do not believe the narrative Mommy Yes, we'll be your final message for Africans living in the diaspora Don't be afraid Don't think have excuses like I don't have this. I don't have I'm too old.   I want to be here I want to be here. I have no plans of ever living in the united states again I am too at peace And if you have never really experienced that if you sit up there worried about what what political group is going to save you They're not They're not gonna save you. You need to come here and save yourself Um, since you're living here on a long-term basis, um, it's the visa application or applying for visa on issue or something The visa application is very very easy President Kagami and the government that supports him have done an excellent job um With that process So yeah, I am on a long-term visa. It's uh, 10 years and after the 10 years I can become a permanent resident That's amazing. I feel like um the government in this country is putting so many so much in place in terms of um Africans coming to rwanda. I think so many africans don't even know that If you are from an african country as soon as you land in this country, it's visa on arrival You don't need to apply for visas in your country See, I'm going to I go to certain countries and I have to apply with my visa in two weeks three weeks before I step in the country But rwanda, so now I go get to the airport Very there. I've got my visa. I want to say that Thank you so much for watching and thank you so much for sharing your experience with me I don't want them to talk too much on this channel because I believe that they have a channel that they're going to share In depth of their life in rwanda with you all so I'm going to play with you. The link will be in the description It's my first to subscribe and be part of the awesome family And um, if you haven't subscribed to order my youtube channel, please subscribe and let's hit Emily and I am my peace out


And from Kaduna we move to a state where pensioners from local and states are demanding for an increase in their quarterly paid outstanding gratuity. They made the request to Governor Dakwa Biadong during their respective stakeholders' meetings in our bell quarter, the state capitol. Because of our choice, in the last payment made, he paid 79 local government pensioners. At this juncture, we are begging all the lovers of the aged in Nogun stage, Nigeria by extension, to please talk to Governor Dakwa Biadong in the language he understands so that the local government pensioners wouldn't toil for 35 years in vain. The government assure that their matter will be prioritised henceforth. However, they called for a review of the pension scheme in line with constitutional provision. Hello, hope you enjoyed the news. Please do subscribe to our YouTube channel and don't forget to hit the notification button so you get notified about fresh news updates.