Good morning. In today's class, we will consider the explosions involving storage vessels which contain cryogenic fluids. We will also consider something on rupture of pressure vessels after we deal with explosions involving the cryogenic fluids. But to come back to the particular point of let us say explosions involving cryogenic fluids let us say, we must first define what a cryogenic fluid or a liquid is. Any liquid which has its boiling temperature under normal atmospheric conditions less than minus 150 degree centigrade that is equal to 123 Kelvin is called as a cryogenic liquid or it is also known as a cryogen. You know we find these cryogens are important not only as a fuel like hydrogen is a fuel may be LNG is a fuel. It is also used for several other applications and the industry these cryogens are used and we would like to understand what are the types of explosions which take place when they are kept in a storage vessel. Like for instance, let us say I want to keep a cryogen in a storage vessel. Apparently you know this is the cryogen and we say cryogen is a low temperature fluid that means its boiling point under atmospheric condition is less than 123 Kelvin. Well the vessel has to be insulated very well insulated. Let us say it is insulated using let us say a double wall construction with vacuum or let us say with several other may be foam may be you have multi-layer insulation and all that such that you like to prevent the heat from the ambient. See the ambient is something like let us say at 35 degree centigrade the fluid here is a temperature less than we say minus 150 degree centigrade. Therefore there is always a tendency for heat to flow in and therefore you give sort of a good insulation multi-layer insulation vacuum insulation may be some powdered insulation may be some puff insulation and so on. And therefore let us say this is it the vessel is very well insulated. Now even if you give the best possible insulation there is always some heat in leak which occurs. There is always some heating which is going to take place. You know may be it is small but still it is there because of the large temperature differences. And what does this heating do? It causes may be you know when I heat this particular surface over here little bit of heating may be the fluid becomes less dense over here because whenever I heat a fluid it tends to become less dense and the fluid sort of rises up. Here it rises up and therefore you have something like the fluid which gets heated in the wall region tends to rise up because it is lighter in density compared to the original fluid and it sort of accumulates at the surface. Therefore you have the convective currents over here which go and cause the current to go like this and you have the migration of the heated fluid which is less dense and you ultimately end up with something like a lighter fluid on top may be lighter fluid on top and may be the heavier fluid at the particular bottom. Actually the lighter fluid is at a slightly higher temperature and with respect to time what is going to happen is you have something like lighter fluid at the top the heavier fluid at the bottom and this process of having because of the heat in leak which takes place and in any vessel however well you insulate there will always be some level of some small heat in leak it heats the liquid and you have this process which is known as stratification. In other words the lighter fluid comes to the top it is little warmer and therefore if I were to now plot the temperature gradient if I were to let us say plot the temperature gradient over here what I observe is well at the top I have temperatures which are slightly higher temperature which is slightly higher may be on this scale I plot the temperature and then I have the temperature lower that means I have a warmer fluid on top resting on a relatively lower temperature cryogen you know this is not only true for cryogen it is only also true you know at home if I have let us say a bucket of water and I put something like a heater coil in this particular water I supply I heat the water what is it we observe you know we find that when the water is heated on top of the water you have hot water at the top for quite something in fact you will find boiling of water takes place but the temperature of water in depth is going to be smaller this is also the same thing like stratification may be the less dense water when it is heated water when heated look gets lower in density it rises to the top and you have the warm layer at top which is called as stratification. Therefore we find well you have stratification warm layer and therefore what is going to happen the gas that is the vapor of this particular cryogen which is on top is also warm at this particular temperature it tends to be in equilibrium and if the more and more warmer fluid comes over here well gases generated and therefore in all cryogenic appliances you give something like a vent wall through which if the pressure increases well the vapor gets lost gets released through this particular vent and when it gets released the pressure decreases well the temperature decreases and you can also control the temperature because once the vapor is released the pressure decreases the temperature decreases this layer is in equilibrium with the vapor here and therefore you have some equilibrium type of thing but all said and done you have to release the vapor in order to keep the pressure in a cryogenic storage vessel constant. Therefore you have the venting of gases before coming to a particular problem let us take a look at three or four cryogens which are used and then discuss what are the problems is there any particular problem associated with storing a cryogen in a particular storage vessel in a well insulated storage vessel but as we keep saying whatever be the type of insulation there is always some heat in leak taking place. Therefore let us put a few cryogens well we can talk of liquid helium well liquid helium as a normal boiling temperature at atmospheric pressure of something like 4 Kelvin you could have liquid hydrogen the normal boiling temperature at atmosphere pressure is 20 Kelvin I could also think of liquid nitrogen which has the normal boiling temperature at atmospheric pressure is 77 Kelvin I talk of liquid oxygen which is at 90 Kelvin the boiling temperature and the last one I talk in terms of liquid methane and the temperature boiling temperature is 111 Kelvin at the ambient conditions well these are the five typical cryogens which are cryogens because their operating temperature is less than minus 150 degrees centigrade or 123 Kelvin. Now if we store some of these cryogens in this particular vessel and let us say if it is not totally pure what do you mean by not being pure you know this is an essential part of it like for instance let us say I store LNG you know if I talk in terms of liquid natural gas and we have been considering this we considered the LNG explosion at Cleveland we said well we talked in terms of natural gas explosion at Ural we talked in terms of the liquefied one which entered the gutters and caused the manholes to sort of rocket up or skyrocket therefore you know when we talk in terms of LNG and this LNG is an important fuel nowadays it is transported all over the world in tankers not only that it is also transported in pipelines and therefore and it is also stored it is also stored in tanks like for instance of Cochin harbour we get LNG we then store it in in huge tanks and these tanks are again as I say well insulated with a vent valve such that if you have vapor which is being formed you occasionally vent it out such that you have this and what happens let us consider this LNG LNG is from the gas fields it is got as a vapor and it contains not only pure it is not pure methane it consists 90% of methane it also contains some other substances and the other substances which contains are in addition to methane the formula should have been CH4 it also contains some ethane C2H6 it contains some propane C3H8 and also little bit of let us say may be petrol like for instance gasoline well if I look at the boiling point temperatures you know well liquid natural gas is stored let us say as a liquid it is stored as a liquid we say well it also contains some impurities and these impurities are all fuels mind you it contains some liquid ethane it contains some liquid propane because the temperature is low the temperature is of the order of something like 111 Kelvin which I can say is may be 273 minus 111 which is equal to something like minus 162 degree centigrade because it is below 0 degree centigrade you know at this temperature may be the ethane which is contained over here is also a liquid propane is a liquid but the boiling point of let us say methane is we say is minus 162 degree centigrade of ethane the boiling point is something like minus 85 degree centigrade for propane the boiling point is minus 42.4 degree centigrade and for gasoline it is something like plus 69 degree centigrade therefore when I consider liquid natural gas which is stored in large quantities in in all over the world you know you you have this LNG is not pure methane at this particular boiling point temperature at atmospheric pressure but it also has other traces of let us say ethane propane and gasoline and therefore what is likely let us consider the problem just I keep the LNG in a particular vessel and since it contains some of these heavier constituents mind you C2H6 is heavier than methane propane is even heavier molecular masses higher well gasoline is something like may be C20H something therefore it is even higher therefore when I store these things in a vessel now I will remove the outer layer I just say well I store the LNG over here what is going to happen the heavier constituents such as say ethane propane and gasoline are all at the bottom because it is heavier therefore may be I say gasoline is over here propane over here and therefore the heavier quantities are at the bottom and the lighter methane which constitutes maybe more than 94% is what is at the top of course you have a vent valve over here and if some some because of the we talked in terms of stratification we said well the thing arises and I have a stratified layer on top this is my stratified layer on top okay now what is going to happen it is not that heating leak occurs only from the side walls but heating leak will occur also from the bottom and therefore when heating leak occurs from the bottom you already have a dense denser relatively denser may be ethane propane gasoline at the bottom and therefore whenever some little bit denser liquid is heated by by heating leak from the bottom well its density decreases but when its decrease when its density decreases for these heavier substances its density could still be less than the liquid methane on top therefore even though it's slightly warmer it tends to still kick be at the bottom because even though it is heated more than the liquid over here more than the liquid methane over here its density is still not less than methane for it to migrate up and therefore it continues to get heated till a particular time when its density let's say liquid density of the corresponding heavier constituents becomes less than that of the liquid methane and therefore you have higher energy or higher temperature over here because it's more than this and this layer of heated sort of heavier constituents of gases is known as thermal overfill therefore now we know when it gets heated because of the further heat in leak well it rises to the top and sort of you know when it rises to the top it it it mixes with the stratified layer and this this what we call as something like a rollover that means the heated thermal overfill comes and heats the top layer which is already a little warmer but mind you now the temperature difference here is quite high it comes to the top mixes with the stratified layer and you get a discrete increase in temperature of the surface layer and mind you the gas over here is at the original stratified layer temperature over here and all of a sudden this increase in temperature is not is such that the vapor pressure of this is not in equilibrium with the pressure here suddenly there's a spurt in formation of a gas something like a flash vaporization and this flash vaporization as we saw in the last class it generates so much of gas that it is not sufficient that it's not the vent hole is not sufficient to vent it away with the result the pressure increases rapidly and you have the burst of the storage vessel therefore whenever we talk of explosions involving storage vessels holding cryogens we talk of thermal overfill that means the initially that means the the the cryogen is not a pure cryogen maybe it contains some substances some some cryogens which are or some other substances which are relatively denser and they can be get heated to a more they can be get heated to a larger temperature before that density matches with the layer above it and all of a sudden when and or when it gets heated to a level where in its density becomes equal or less than this well it rises up we call this as thermal overfill it mixes with the stratified layer on top namely a rollover process in which thereafter this flash vaporizes because it is at a higher temperature and the bursting of pressure vessel occurs therefore whenever we handle cryogens which are somewhat impure you have mixture of some other substances which are there such explosions are likely but in the case of LNG well it it is obtained as a mixture of some substances it is not pure methane by itself and therefore LNG has to be the storage vessel has to be designed with care such that the thermal overfill and rollover will not cause an explosion. Having said that it is also important that we talked of LNG on and off during the earlier classes we find that well you know we have tankers in the ship which are designed to take this low temperature fluid across the different oceans we have the LNG over here and you know in if by chance let us say a ship containing the LNG leaks out supposing there is a leak on the surface of water in in a sea then you have a LNG which is being formed and we said this is very dangerous why did we say it is dangerous because if LNG leaks over let us say the surface of the earth because the LNG is very cold it immediately cools the earth and also maybe it tries to it flashes into vapor because its boiling temperature is very low but when it flashes into vapor it absorbs the latent heat from the liquid over here and therefore the rate of evaporation comes down with time whereas if the spill occurs over water in a ocean because of the turbulence of the ocean and also the convection movement of water below the convection of water which takes place you know the spill continues to evaporate you have a very copious amount of LNG and therefore LNG requires some caution when we transport it by sea or even for that matter LNG being a cryogen it has to be handled with care and there are problems such as as we say explosion in pressure vessels holding LNG and it has to be adequately designed to hold the additional pressure. Having said that you know we were looking at the explosions involving cryogening fluids there is another instance or another phenomenon which can again cause the explosions in in the storage vessels. Let us take a look we said earlier that you know you have the storage vessel you have the cryogen which is kept in a storage vessel now let us say I have a storage vessel like this I have a vent valve because whatever said and done you cannot you cannot avoid the stratification you have a stratified warm layer at the top and this keeps on the amount of stratified layer is shown shaded over here this is the stratified layer and therefore the evaporation takes place and therefore you have to essentially vent of the gases you know when you went off supposing there is a sudden vent of gases and if you went out the gases what is happening there balance gas because of the expansion that means the pressure gets reduced there is expansion the gas over here cools down when the gas cools down well you know it is almost at the saturation temperature saturation temperature corresponding to this and if it cools down well it is below the boiling point of the vapor at the particular condition of pressure over here and therefore we expect when it cools down it should sort of get back from the vapor it must become a liquid but the the process of condensation that means the vapor becoming a liquid takes some time and very often with sudden venting what happens is you form something like a meta stable vapor which is a vapor at a temperature less than the boiling point corresponding to this particular pressure in other words you know it is tending to condense to the liquid but it is still a vapor and it is there as it is and therefore when when you have regions cold regions over here that is the walls which are cold and therefore all of a sudden this meta stable vapor cannot exist as a vapor it is waiting to condense and therefore all of a sudden you have condensation taking place and therefore you have this condensation taking place of the vapor may be near the surface and any condensation to condense you know you have to reject heat and therefore the condensation has some heat that means and this heat which gets rejected can drive a shock wave and such a shock wave driven by condensation is known as a condensation shock. We can readily show this on the our Eugenio namely I have pressure versus 1 over rho the initial conditions corresponding to the cool down conditions can be shown by the initial conditions P0 and rho 0 and what is it or let us say 1 over rho 0 because my scale is rho 0 here I have P0 into 1 over rho 0 and since some heat is associated with condensation I have something equivalent to a condensation process over here which is let us say meta stable and when it condenses I have heat which is getting generated I can always form a shock with some particular velocity and this velocity the Mach number of the condensation shock is in general small it is of the order of 1.4 in fact these are encountered in any process in which you have a rapid cooling of the vapor like in a wind tunnel you have this problem in you could have it in the case of these storage vessels but anyway you know you have a shock and these shock will increase the temperature will also increase the turbulence will lead to more flash vaporization and this could also be a cause for explosions of storage vessels therefore we can summarize by saying well when we consider explosions of maybe cryogenic liquids in storage vessels well the thermal overfill and rollover associated with different constituents in the cryogen and secondly condensation shock could contribute to the explosion well this is about the explosions of cryogenic storage vessels let us move to the next topic which is let us say something similar we say well why cryogenic fluids you know any pressure vessel can can explode like for instance I have let us say a compressor the compressor is used to charge a storage vessel of air let us say I keep on supplying the pressure at higher and higher pressure well by chance if my regulation system is such that I supply I pressurize it to a very high value well this storage vessel could just explode could just rupture therefore we would like to find out what is the energy release during rupture of a closed vessel now to be able to do that let us again formulate it it is quite simple we have done something similar earlier let us consider a storage vessel of let us say volume v let us say it ruptures at a pressure p0 and let us say the volume is also let us say v0 of this particular pressure vessel let us say that the thermodynamic properties of the gas are such that it has a specific heat ratio gamma the specific heat ratio gamma is equal to cp by cv we have been looking at it for the different gases and we will find well gamma also plays a major role let this pressure vessel which explodes at a pressure p0 let the ambient pressure be p ambient let the ambient temperature be also t ambient let the temperature here be let say t0 corresponding to pressure p0 over here you know I want to find out what is the energy released in this particular rupture and how do I say well the energy released in this rupture let us say e is equal to the initial internal energy which is contained by the gas over here mind you it is a constant volume explosion therefore I say well the initial value of the internal energy over here minus the final value of the internal energy of the same volume here and what is this equal to this is equal to per unit mass I have small u that is so much kilo joules per kilogram into the initial mass of gas let us say is m0 over here m0 into ui minus when the explosion has taken place in the same volume I have final mass over here and let us say that the internal energy is small uf so much kilo joules per kilogram therefore it is equal to mf minus uf over here therefore I want to solve this I am interested in finding out how much energy is released during the particular rupture and therefore let us put things together I have e is equal to m0 you know I can write internal energy we have seen internal energy is equal to cv t that means t u that is the initial temperature over here minus mi into cv into the ambient temperature because once rupture has taken it is the ambient gas which is occupying occupying this volume well the final pressure is equal to the ambient pressure because nothing is there over here we also have well cp minus cv is a specific gas constant or cv I take it in terms of gamma over here is equal to r over gamma minus one specific gas constant in terms of kilo joules per kilogram kelvin and therefore I can write this as equal to m0 into r t0 minus I have mi into I have r into t ambient divided by gamma minus one all what I have said is I have substituted cv is equal to r gamma minus one and I take gamma minus one common in that particular denominator and here the assumption made is gamma for the gases over here and gamma for the gases here is same which need not be so a high temperature gas has a lower value of gamma as we shall shortly see but when I look at this particular expression from gas equation I have pv is equal to mrt specific gas constant and therefore I can write this mrt0 is equal to the initial value of pressure let us say p0 is what is said is the pressure over here into v that is the initial volume the volume does not change we said that the volume is v0 minus the final volume is again v0 mrt0 corresponds to the ambient pressure over here therefore this becomes p0 v0 minus p ambient v ambient divided by gamma minus one or rather the energy released if I take v0 common because the same volume is there I get v0 into p0 minus p ambient divided by gamma minus one which is the energy which is released during the rupture of a pressure vessel. If I say well this is there I find you know I find that well you have gamma and you know for air gamma is 1.4 you find that small changes in gamma is going to affect the energy release therefore let us take a look at gamma what are the factors which influence the gamma because you find well it is not only the volume and the initial pressure but it is also the the value of gamma which is influencing the energy release and therefore let us let us see what what gamma represents in fact if you go back and see the Chapman Juge velocity for a detonation we also got it as equal to 2 gamma square minus 1 into q there also it was a strong function of gamma and we found well gamma changes between the unreacted gas reacted gas we took it to be common but here also it is sensitive to gamma therefore I think it is necessary to be a little more clear about what are the factors which affect gamma well let us say if I have something like a mono atomic gas something like helium let us say it is a simple gas you know it is just a gas which has let us say mono atomic it has only three degrees of freedom it can move in three directions therefore the degree of freedom it has is three if I take a diatomic gas like air like I have nitrogen oxygen and which constitutes air I say it is diatomic well it has it is it is double therefore it has three translational degrees of freedom it can also rotate in two directions therefore the degrees of freedom are five therefore if I keep on increasing the the complexity of a gas like for instance I take something like let us say di trichloro some are refrigerant let us say trichloro trifloro let us say methane which is used as a refrigerant you know if I consider this you know it is much more complex and the number of degrees of freedom are quite large in this case it is it is it is of the order of something like maybe 10 15 or so and therefore you know when I heat a gas again you know what I do is I increase the degree of vibration levels of the gas goes up and therefore its degrees of freedom that means I convert some of the energy into the vibrational modes of a gas and if it is vibrational modes of the gas the degrees of freedom goes up if it is rotational modes the degrees of freedom goes up and it is possible to connect the gamma to the degree of freedom as say 1 over 2 by the degree of freedom this is this comes from the kinetic theory of gases and therefore you find that for monatomic gases such as helium which is a degree of freedom of 3 it is equal to 1 2 by 3 is the value of gamma which is equal to 1.67 for a diatomic gas it is 1 2 by 5 which is equal to 1.4 and for a gas like trichloromethane or dichlorodifloromethane it is of the order that is gamma is of the order of around 1.1 and therefore for a heated gas in which it is very hot maybe the gamma will be very low and when we talk of a low value of gamma apparently I am in my denominator I am having gamma minus 1 therefore the denominator becomes a small number and therefore the energy release goes up. Therefore let us do a small problem to find out the sensitivity of the energy release in the explosion of a pressure vessel with respect to the value of gamma. Therefore let us do this problem let us say I have a pressure vessel which holds air whose gamma is 1.4 at a pressure of let us say 10 MPa. Let us say the ambient is ambient pressure is 100 kilo Pascal which is 0.1 MPa. This is in the other case and this vessel let us say this vessel burst at a pressure of 10 MPa. I also consider another example wherein for the same volume let us say the volume is 1 meter cube so that I do not need to carry the volume. I have the same 1 meter cube vessel having a pressure of let us say the same pressure 10 MPa. Ambient pressure is 0.1 MPa as earlier but it contains let us say refrigerant gas and this refrigerant gas has a gamma let us say equal to 1.1. Now I want to find out what is the energy release in the two cases. I just use my equation we have derived this E is equal to 10 MPa that is 10 into 10 to the power 6 Pascal minus 0.1 into 10 to the power 6 Pascal that is P not minus P ambient divided by gamma minus 1 and into the volume which is 1 so much joules is what is generated over here. In this case I have a similar expression I have 10 into 10 to the power 6 Pascal minus 0.1 into 10 to the power 6 Pascal divided by in this case gamma minus 1 is equal to 1.4 minus 1 in this case it is 1.1 minus 1 into volume so much joules which is generated therefore in this case I take 10 to the power 6 outside 10 minus 0.1 is 9.9 divided by 0.4 joules and in this case I have again 10 to the power 6 into 9.9 divided by 0.1 you know if I solve for this I get a value of the energy release being something like 24.75 into 10 to the power 6 I can call it as mega joules in this case it is 99 mega joules and therefore you find yeah you know the energy released when I have something like a complex gas is much very much higher for the same conditions compared to air the question is why should this happen why should an explosion of the gas at the same pressure same initial conditions same volume and same ambient conditions release much more energy the thing is that a more complex gas because of its different modes different degrees of freedom because of its structure can hold much more internal energy that means the initial internal energy of this gas is very much higher than the internal energy of this gas and since we are talking of the drop in internal energy well the complex gas gives me much more energy but why should the internal energy change and not the enthalpy h is equal to u plus pv it is this which decides the internal structure which holds the energy this is just flow work which does not change substantially therefore cv tends to be high for the complex gases and since it has high it holds much more energy this is the logical conclusion having seen the values or having estimated the energy release in a rupture of a pressure vessel let us go ahead and try to ask one more question you know we said energy is liberated in the explosion of a pressure vessel that is the rupture causes energy to be released and it is this energy which creates a blast wave and we will see the effectiveness of the energy release when we talk of TNT equivalence after some three classes however in all let us consider this energy release could be very slow could be very fast whenever we talk of a constant volume explosion well it just goes with a bang that means the energy release is very fast compared to a constant volume explosion if I have something like a constant pressure explosion what do you mean by a constant pressure explosion well let us say well I have a piston which is driving the gas at constant pressure and the volume increases well that could also drive provide some energy with which I could have an explosion taking place and what is the value of the energy release let us say I have a constant pressure therefore I have something like a piston pushing the gases at constant pressure and let us say there is no change in the pressure of the gases let us say that the initial volume is V2 and the final volume is let us say V1 that means I am talking in terms of constant pressure into V2 minus V1 is the work done which is the energy of the a constant pressure process what we are talking of you know what would be if I were to consider this constant volume explosion derived from the thermal energy which is supplied to this particular volume and also a constant pressure explosion by the thermal energy supplied for this particular change is there something like this being more effective this being more effective I want to find out what is the conversion factor for the thermal energy into the the energy that is the mechanical energy obtained in the particular rupture therefore let us let us let us do this particular problem it gives us a feel of how much energy how spontaneous energy is takes place in a constant volume and the effectiveness of the explosion and therefore when I consider a constant pressure explosion well we say energy is equal to P into we say it is equal to the V2 minus V1 and what is the heat which is drives this particular explosion the energy supplied is equal to Cp that is the mass of the gas into Cp into I have T2 minus T1 or rather T1 minus T2 that is the heat that is this the final temperature minus the initial temperature and I can write well Cp minus Cv is R therefore Cp is equal to gamma R by gamma minus 1 therefore the heat which is supplied is equal to m gamma R T2 minus T1 divided by gamma minus 1 and now I do the same thing mR T2 is equal to the value of pressure being constant P into the final volume let us say V2 minus I have mR T1 the same pressure into V1 divided by gamma minus 1 we have to take gamma into mR T is the P2 V2 I still have to retain this or rather Q is equal to I have gamma divided by gamma minus 1 into I have P V2 minus P V1 divided P V that is about it that means I have gamma by gamma minus 1 into P into I have V2 minus V1 what is the work done work done is equal to P into V2 minus V1 this is P into V2 minus V1 into gamma minus 1 therefore if I take the ratio of the work or the energy which is released in the particular constant pressure process let us say I have E I say constant pressure process divided by Q in a constant pressure process I have P V2 minus P1 P V2 minus V1 cancelling and I get E by Q is equal to gamma minus 1 divided by gamma if I do the same thing for a constant volume explosion we form that the energy released in the constant volume explosion is equal to V into gamma minus 1 into we had P that is the P0 minus P1 or P ambient and we also find that the energy heat which is supplied to do this I can write it as equal to I have M C V into the T2 minus T1 which I can now write as as equal to M R divided by gamma minus 1 into T2 minus T1 again writing M R T2 and M R T1 as equal to P0 V and P1 V I get this equal to V into P0 minus P1 divided by gamma minus 1 and therefore for a constant volume energy release divided by constant volume thermal energy what is required is equal to V same expression therefore it is equal to 1. Therefore we find that the since gamma is of the order of 1.4 the energy release in a constant pressure process is much lower and we know that a constant pressure process is a slow process whereas when I talk in terms of a constant volume explosion it is a sudden process and therefore now I can plot as a function of time the value of let us say energy divided by the heat release I say well for a sudden process I have this equal to 1 and as I move towards a constant pressure process the value I get is gamma minus 1 divided by gamma therefore the suddenness of an explosion is important to be able to convert all the thermal energy into the mechanical energy you know this completes what we said is about the the rupture of pressure vessels about the energy release and we find yes now we can estimate the energy release but there is one one small problem which very often the chemical industries face and let us quickly go through it you know the problem is like this you know in in any chemical plant or any any plant you have a series of reactors you know we are you are trying to form some substance like like for instance let us let us go through one one particular example let us take the example of the explosion which happened at Flixborough in UK where and on June 1 1974 there was a spillage of let us say cyclohexane which mixed with air and and just ruined or made Flixborough into a ghost city you know what happens in a chemical plant you have somewhat like you have reactors several reactors which are essentially storage container storage vessels you have let us say reactor one reactor two over here I have reacted three over here yeah several of these reactors and all these reactors are always connected by pipelines because from one reactor I transported to the second reactor to the third reactor to the fourth reactor and so on now the question is supposing by chance in one of the reactor there is an explosion I do not want my entire plant to get to to to get damaged I would like to still protect my second reactor and third reactor and somehow ensure that the explosion from reactor one does not get into reactor two or rather I am interested in so designing this this pipeline which connects my different reactors should be such that let us say its diameter must be d and let us say its length must be l I am interested in the connection having a particular diameter d and a length l such that explosion from one reactor does not get into this even if this explodes can I still save this is the question therefore we are looking at this particular connecting or let us say the pipeline and we immediately say well I have studied this if d is less than the quenching dimension or rather in the case of detonation if d is less than the critical diameter well my problem is solved film cannot travel but the problem tends to be a little more complex there are additional factors which are involved and that is what I want to highlight now you know let us say well in the reactor one I want to simplify it I want to put the scheme as well I show the reactor through some another geometry let us say I have one reactor in which there is some explosion taking place well it is a donor as far as an explosion is concerned it is connected to a next vessel which receives the explosion I call it as a receptor well I am interested what must be the diameter of this pipeline and what must be the length of this pipeline to make sure that the explosion does not travel from one one particular reactor to the other therefore now I tell myself supposing let us say that the diameter of this particular connector is such that it is somewhat same as the surface area of this particular vessel or rather if I save volume and I say mean surface area if the surface area cross-sectional area of this vessel is same as something like let us say this diameter is d is same as let us say surface area corresponding to volume one is same as let us say pi by 4 into d square well I have such a huge wind that may be a flame gets started you know whenever gas is getting generated you know it really cannot build up pressure here because the the vent is so large that it just allows the gas to go through and therefore in this case there is no danger at all but to think in terms of a large vent and why does it happen the vent area is so large that means before pressure with time tends to get build up at the low pressure itself it starts venting the gases and therefore you have something like a gas going over here and therefore it is a unburned gas mixture which goes out even if it is burned the if the diameter is less than quenching thickness well it quenches nothing is going to happen well it's it's safe but in practice it's not possible in practice d the diameter or the surface area is going to be very much smaller than this and therefore since the vent area is much smaller than the original cross sectional area this happens like a constant volume vessel or a constant volume reactor which is exploding and in a constant volume explosion the maximum value of pressure is pm which we have hydrocarbon we said it's between 5.7 to something like 7 atmospheres if it is hydrogen it is of the order of 11 atmospheres and therefore I have a constant pressure explosion which gives me a high value of pm and therefore what is going to happen you have a high value of pm and therefore the gas comes in here you know it comes at high pressure and it and it expands into this donor into this receptor vehicle that means let's say v2 as a hot jet if this hot jet comes into this particular reactor over here and if this hot jet immediately mixes with the cold reactive gas over here or with the with the gases in this particular volume what is going to happen well this jet gets extinguished and therefore it is not possible for you to to initiate combustion over here and since I am that means I am talking of if the mixing of the jet with the gases here is very rapid that means the mixing time let's say tm is a very small number well I cannot ignite this gases because it gets quenched. However if the hot jet comes and the chemical reaction occurs so rapidly that heat is getting generated well this also explodes or rather if the chemical reaction time let's say tc of the gases here is a small number well this this container or reactor explodes therefore we find the ratio of tm by tc if the mixing time is small well I am safe therefore for safety I say well that mixing time divided by the chemical reaction time must be less than a particular value and this also therefore becomes an important parameter it's not only the quenching distance and mind you you know whenever we do these things you know we also talked in terms of quenching distance divided by the flame thickness or critical tube diameter for a detonation let's let's concentrate on flame d cube by tf we said is is of the order of something like 5 or 10 or something of this order we also were able to put the quenching diameter in terms of a peclet number that means the convection heat transfer divided by the conduction heat transfer you know but it's very difficult to to theoretically determine this particular diameter and in practice what is done is we we derive it from experiments and the quen the diameter so derived from experiments is known as maximum experimental safety gap and it is known as MESG it is derived for the different gases and we know what must be the type of diameter what is used it is also necessary that the length must at least be of this diameter such that the heat losses and the active radicals loss to the walls will quench it and in practice we use the maximum experimental safety gap but in addition to the safety gap we must also look at the phenomenon by which things takes place the relative size of this relative to this volume the mixing times and chemical reactions times in order to make sure that explosion in one vessel does not get into the other vessel well this is all about explosions in the cryogenic vessels rupture of pressure vessels and also something on containment of explosions in a particular reactor and not spreading to the other in the next class what we do is we go to a slightly different topics we have been restricting ourselves to gas phase and dust explosions we will take a look at the condensed or the solid explosives in the next class in the next two or three classes we will deal with condensed explosives thank you an announcement please the lectures between numbers 28 to 32 covered the different categories of explosions the references for further reading on these lectures namely those between lectures 28 to 32 and a set of homework problems pertaining to these specific lectures are given in the downloads of this video course


Buenos dias, Puerto Rico. Good morning and welcome to the ICAN 79 Community Forum. It is truly an honor to stand before you today here in the beautiful city of San Juan. On behalf of ICAN, I would like to thank our generous sponsors and hosts. I would also like to express my gratitude for the warm reception we have received. The last time ICAN held an in-person meeting here was in March of 2018, not long after Hurricane Maria devastated the island. The resilience of the people of San Juan is remarkable. I am heartened to see that the city has been rebuilt and is even more vibrant than before. We are honored here to be joined by dignitaries from the Senate, government and academia representatives, the CEO and president of DotPR, esteemed guests, and the Internet community. Whether you are here today in person or joining us online, your presence underscores the strength of our shared commitment to the future of ICAN and to ensuring a secure, stable, and unified global Internet. As we embark on the first ICAN public meeting of 2024, I want to first reflect a bit on last year, which was defined by changes and major milestones for ICAN. 2023 began with the appointment of a new interim president and CEO, and September marked ICAN's 25th anniversary, which we celebrated together at the annual general meeting in October. Throughout the year, we navigated the dynamic and complex digital landscape to fulfill our mission. Perhaps the most significant development for ICAN last year began when the board formally initiated the process to open the next round of new generic top-level domain applications. Months of collaboration ensued, involving the community, organization and board, resulting in significant progress towards the launch of the next round in April 2026. This ambitious endeavor underscores our commitment to expanding the domain name system with inclusivity in mind. Over the past year, the ICAN board continued to build on our commitment to strengthen collaboration with our Internet ecosystem partners, particularly with the numbers community. These collective efforts and problem-solving have resulted in measurable progress towards our common goals. Members of org and the board now have regularly scheduled meetings with our RIR colleagues. Also, this past January, we met with the board of the Latin American and Caribbean Internet Adresses Registry to leverage our synergies and strengthen our partnership with the five RIRs. On behalf of the board, I would like to thank each of you for your tireless efforts to achieve our shared goals and fulfill our mission in the past year. Your commitment to collegiality, compromise, and creating a safe and inclusive environment is truly commendable. At the start of another transformative year for ICAN, I can see that we are united in our belief in a unified global Internet. Last year marked another major milestone for ICAN, for only the third time in the organization's history, the board took the first crucial steps in the development of ICAN's strategic plan for fiscal years 2026 through 2030. The strategic plan serves as a roadmap for the next five years and consists of specific, tangible objectives that will enable us to continue to fulfill our mission while striving towards our collective vision for the future. In other words, the strategic plan is the foundation for everything we do. However, charting a course for the next five years is not for the board to undertake alone. It is a collective effort that must involve all of ICAN, the board, the community, and the organization. Your unique insights are essential for developing strategies that will help ICAN anticipate challenges and seize opportunities in a rapidly evolving Internet landscape. Many of you are already actively involved in the strategic planning process, which is still in its early stages. As the process advances, I encourage all of you to review what we have done so far and to contribute your ideas and feedback. In particular, I urge you to participate in the strategic planning session that is happening on Wednesday. The board is working to fulfill its critical responsibility of selecting ICAN's next president and CEO. Last year, we held listening sessions with stakeholders from across ICAN and the Internet ecosystem, whose input helped shape the candidate profile and position description. I mentioned a year ago that ICAN is at an inflection point and faces a gamut of challenges. In the next president and CEO, we are looking for an individual with transformational leadership who inspires action to effectively and relentlessly execute on multiple fronts and will modernize the organization and its processes, implement policies successfully and in a timely manner, build even stronger partnerships within the ecosystem, reshape ICAN to be an exemplar multistakeholder model and work effectively on the global stage with other world leaders in this critical space to reaffirm an inclusive multistakeholder Internet governance paradigm. The search process is ongoing but well advanced. It has yielded an experienced and diverse candidate pool from across the globe. The board is diligently working towards identifying the individual who has the right temperament and balance of personal management and technical skills to lead ICAN during these exceptional times and into the next chapter of its journey. Indeed, we achieved much in the past year with the culmination of many areas of work. However, there is no time for rest. We face numerous challenges ahead and we must remain at the ready, sustaining a commitment to timely project delivery is crucial and recognizing the efficacy of collective effort will propel us further and faster. As we navigate to pursue our goals and navigate our own challenges, we must also recognize the mounting pressures on the multistakeholder model of Internet governance. This model, driven by collaboration and shared responsibility, has produced a consistently stable and functioning domain name system for over 40 years amid exponential growth in Internet traffic and users. Multistakeholder governance has allowed the Internet and the digital economy and services to flourish while protecting it against unilateral decision making and top-down control. This model empowers participants from all sectors to come together as equals to share their views and work towards consensus-based decisions. This broad inclusivity and democratic participation has yielded a system of voluntary standards, best practices, cooperation, and trust. In 2005, the international community, including all governments, accepted the multistakeholder model of Internet governance during the World Summit on the Information Society. They recognized the vital roles of all parties in maintaining and evolving the Internet as a global resource. Next year, the United Nations will review the WSIS outcomes and the UN General Assembly will have the opportunity to reaffirm and improve on the achievements of the WSIS. The discussions have already begun amid the consideration of a proposed global digital compact which is expected to be adopted at the UN Summit of the future in September 2024. At this watershed moment for multistakeholder Internet governance, ICANN, along with our technical partners, must showcase the strengths of this multistakeholder model and contribute our insights to the broader global conversation about the Internet's role in shaping a sustainable and inclusive future. As we embark on this new year, we must continue to be bold, resilient, and agile. We must continue to challenge ourselves, to take a hard look at our processes, and to experiment with new ideas and approaches. It is only through evolution that we can continue to deliver the most impactful outcomes expediently, yet without sacrificing quality. We are strongest when you work as one and together we can overcome any obstacle we find in our way. The current times are complicated. The global geopolitical landscape is fraught with aggression. As is typical with such situations, unthinkable collateral damage is done to innocent and good people. From different walks of life, from different fates, and from different ideologies. Emotions and sensitivities are high. I urge all participants, whether you are here in person or online, to focus on the work that needs to be done here at ICANN 79. Please rise above the fray and reach out to each other in good faith and on the grounds of our common humanity. I implore you to take the high road and think before you say or do something that could be potentially hurtful to someone. We are here to further the mission of ICANN, and I ask that we immerse ourselves in the work and spirit of that mission. At this community forum, the board is looking forward to the discussions, collaboration, and insights that will unfold over the next few days. The internet's identifier systems continue to evolve and ICANN remains committed to promoting a unified and reliable internet within a sound framework of global multi-stakeholder governance. Only the multi-stakeholder model of internet governance will allow us to continue to meet the needs of internet users, including those who are online today, as well as the next few billions who are not yet connected. Your dedication to our mission serves as a powerful reminder that, together, we can build a future where the internet remains a force for good. On behalf of the ICANN board, thank you for your hard work and commitment. Let's desayu una exitosa reunión y que disfruten Puerto Rico.


Hi everyone, can you hear me sure sure Yes, right there. Hi So I'm going to wait for a few minutes if more people show up Hopefully more people will show up than just the regulars and the interested parties Normally we wait for about two or three minutes. Hi guys One more minute and we start And by the way the session is being recorded, so we can have Reserve the session and Make it available for people who are interested. I think the attendance during these Holiday months are going to be very challenging Because normally people just drop off and they do not show up But today we have seven so far and We are waiting for one more minute before we start We are waiting and I think we are going to start in a second First of all This session is meant to be a look back and a look forward at the next year there are a lot of exciting things happening a lot of things are a lot of Conferences Everything else going on at the same time So I guess it's a challenge to host an open source meeting like this and to have good participation First things first we have to do a couple of administrative things one is the The fact that We are operating under the Linux foundation and hence we have to stick by the Antitrust policy Which you can read in detail and that is one of the requirements the other is The code of conduct which says That even when disagreeing with people You cannot be disagreeable and also Give credit where credit is due and do not harass people which are you know common sense sort of Things that We all can agree with I hope so without Waiting too much. I think I'm going to just start to ask see to talk about the The youth that he has found in the Work that we have done previously which is basically created a Working model of a wholesale CBDC in five hyper ledger labs Obviously used certain Properties and it made certain assumptions Which you know, it's a it's a general Tokens uses a general token standard taken from TTF And now migrated to IWA So that is That's the interesting part The more interesting part to me anyway is the fact that This can become the basis for creating other tokens with changes as the notes in his In his Wiki page where he has gone into great detail on what is What is necessary to make the token work For a carbon For a climate accounting Where which he has proposed three types of and also proposed We do the analysis in a similar way which is We basically go through the roles that are needed and the property and the behaviors that are needed and Additionally, he has also proposed certain properties We are in the process of proposing the new properties to the IWA because They need the input from people like us Although they are a closed system in the sense that you need to be a member to contribute but they have Even me a observer status and also checking credentials on their website, I mean on their github so on the github I can do a PR if We can agree on what is needed and then they they'll either accept it or not accept it But it doesn't matter because we can have our own private fork and create those those properties ourselves and also use the private fork Including all the other tools that they have in order to create all the artifacts the key Key element of this is that it goes from a business use case modeling perspective to the actual artifacts needed and It also creates an output in the form of a PDF file that can be used in a business context with examples other prop other things that are More palatable to a business Perspective so it unites the business perspective with the technical perspective because Goes from the formula to you know a PDF file to everything else Anyway, I don't want to hold up too much of the time since he's here And I would ask him to speak a little bit about the use and the To have people add on to this to the climate change Channel that he has created and he's been very active in this in this fear And also he has made a presentation here a long time ago on On tokenization Which which is also available I Want to surface it to others anyway, go ahead see you can you can also share your screen if you want to And we can Go ahead, I'll mute myself and give it enough time for others to react Also, we have to talk to these people about what our plans are for 2021 Okay, great. Hi everybody. So nice to meet you and thanks for the introduction Beepen. So this came about Actually about a month or more ago when we were working on how to create tokens from emissions calculator from utility bills and I was thinking back to some of the examples when I Have worked as a fund manager and we worked with a lot of securitizations and how to link basically a Non-fungible asset or non-fungible data records to a fungible token in a way that Loans which are non-fungible are pulled into a security which is fungible and so we had a little discussion on your mailing list with you and money and Subsequently actually money and I spoke and he Explained to me more about what the e-failure project and the code base that you've created actually does so I Thought about it and actually I realized that Obviously what you created is a wholesale central bank currency but it could also be used to model emissions tokens in a variety of Systems, so I create I started working on this we went through your CVDC examples and and looked at what it did and we came up with this which is a page on the wiki and it's a Basically an emissions tokens network that could be used to trade and record and and transact in emissions and offsets so I won't read through all of it for I'll just leave most of this here because some of this obviously like the unit of some measure quantity and Whatever these are specific to us in the emissions field The way that we're doing this is is in a lot of ways similar to how your CVDC works We have three types of tokens The results of an emissions audit carbon offsets and renewable energy certificates And so here instead of having a central bank. We could have one or more Authorities that could mint these tokens and then once the tokens are minted There could be Certifiers or auditors who would then issue them. So these are entities that review data and records from climate projects or from business operations and determine the amount of emissions and Then they could then from that data mint a token and place it on this network And then the other thing we thought we should add is then those people would be able to register their customers which are everyday businesses and consumers on the network and Those consumers and businesses would then start to trade or transfer tokens to each other as a way to transfer emissions Offsets with each other and finally there's the What's different here is you have this concept of burn with a currency where currency is removed from circulation This unfortunately doesn't happen with emissions. They don't get removed from the atmosphere very easily But there is a similar concept called retire So when a token is retired That means it's permanently counted towards your emissions total and it can't be transferred to anybody else so Basically, we have a set of operations and a set of players that are very similar to what you have in your central bank digital currency and I go through some examples of what the fields are And just with this kind of a network we could do some interesting things like for example, there are these cap and trade mechanisms for emissions So we could have This kind of a thing based on your CBDC model a cap and trade regime Okay, where the central authority the central bank becomes the cap and trade authority basically the government agency that runs it It would issue allowable emissions to all the different members all the companies that are allowed to emit Greenhouse gases and then they could trade them amongst themselves And then as the emissions are counted Like during an annual audit that tokens are retired. So then you keep account of how much different people have used versus Had purchased in terms of their cap and trade total and then That's so that's one possibility another is these green banks which finance Climate projects energy efficiency renewable energy type of projects and they could use These kind of tokens to account for the actual effect of what they do So those are just a couple of interesting examples here And then I know VP you had asked about this event that took place a couple weeks ago Called the open climate collab with them So I'll just go over really quickly because I think there's also a thread there that will be of interest to you guys So the open climate collab with them happened. I think earlier this month and it was three days of Basically sessions on a lot of different climate related topics. You had people talk about the Paris Agreement talk about fine mitigate Data standards And a lot of it, you know, it's very specific to climate and to land use or Climate offsets and calculations, but what was interesting in the discussions, at least for me and I think maybe for you guys as well, is there are a couple of currency related initiatives. So there's this group. Okay, and they're creating what's called a community currency involvement. So what the idea of this is They decide on projects that benefit a local township and then for people who are doing those projects. As you see in these pictures, they get The equivalent a currency unit that they can spend with just the local businesses in that community And apparently I'm talking with them. There's an example of this called Sardex, which is a In the Italian island of Sardinia. This apparently has gotten some volume of usage And it's a way to incentivize local action and local credit systems. So this is kind of this is a currency that ties Things like climate and social projects together. And then This is another project that I had actually heard about through the open climate clabbathon through an economist and also a presentation there. So Deldin Chen is in Australia and he's worked on this idea of basically creating a global carbon reward, which becomes a central bank asset, a reserve asset and against which the central bank is Could issue currency units against. So basically the idea is that the central banks could then directly through issuing currency fund climate reduction and risk mitigation. So this Obviously then links exactly what we're talking about. Here with emissions calculations very directly with a central bank digital currency and I had a conversation with him and told him about your project and he's he was very interested in what you're doing as well. So maybe there'll be some interesting synergies for you guys. So I think that what was interesting is that your focus obviously on Central bank digital currency in Financial sense but within the climate climate, And I think that's a good point. So I think that's a good point. And I think that's a good point. Is that your focus obviously on Central bank digital currency in Financial sense, but within the climate community, there's definitely an interest in creating alternative parallel community different types of currencies. That are tied to climate action and social goods. And so this might be another place where you could see Projects such as your e-failer project being used. And so I guess that's just my introduction. I'd be happy if anybody had questions to answer them. Does anybody have questions. Bobby hi, it's Bobby. How are you. I say how are you doing. Good. Nice to see you again. Great presentation. Every time I hear you, it's growing and developing in such a positive way. Okay, thanks. I'm just putting my thinking cap on here and just seeing so now that these this net emissions token network framework is being thought of and starting to be put in place. For you, what are the next steps and how can the community help get this actually Using we have people using it. Yeah, that's a great question. I think you know we want to deploy this so my very short term goal is to get utilities data tokenized on a real production net emissions token network. So we could sign up put in our utility bills and each of us could get a record of our emissions from our utility bills. And then collectively we could go buy some renewable energy certificates or offsets to offset our utility emission. So, relatively simple use case but it will prove out all the technology pieces in a real environment like sending sending data and recording it and seeing it and transacting and then from there, we would expand on it. So, part of that is signing up people who want to try this and I think in the initial stages. It probably would be other open source developers hyper ledger community developers like ourselves who would like who are interested in both in the climate aspects but also the technology of it. Great, thank you. Money. Yeah. Hi, hi. Yes, it's great presentation. Just to follow up on that. Thank you. We definitely we have actually not only beyond CBDC we did that proof of concept and we added ESG tokens as we discussed in our calls. And that's, although it is not in the open source but it's just a token from a commercial perspective. ESG tokens will have a bigger impact on the capital markets. So that's another area where we know there's a real applicability of this and beyond CBDC. The question for for you is that is, while you're working on it, a couple of things you would like to see is that is how much of it is how much of your work can be on the open open source number one. And also considering the fact that you have documented a lot of those token definitions, maybe that could be another area we can consolidate and make it like more like a common mini standard for capital markets as to how you define tokens, whether it is carbon or CBDC or ESG, now there's a separate thing called TTF, the TTF gives you more of the behaviors of the token, but beyond that there is more capital market oriented properties we need to capture. So that may be of help as well. So your thoughts on that would be great. Yeah, thank you. Well, most everything that I'm showing you here we plan on making open source. So actually, some of what could be beneficial to you is we're going to be developing a client for this emissions token network and I think it will probably pour over to the E-Failer network pretty easily and work. At this point we're thinking about using some of the, I guess, Ethereum, Dapp, or Dapp framework and technologies like Node.js and wallets and so on. So this could be a way for you to actually create something for the E-Failer project that could be more of a consumer facing access to that CBDC as well. But everything that I'm talking about we're planning to make open source. And yeah, I would love to contribute any of this towards any standards or just help with that if anybody's interested. So certainly. So first of all, I like to say thank you for showing up and being so engaged to make a couple of points here. One of the points is that the name Thaler comes from Joachim Stahler, which is a coin that was created locally in Bohemia in 1518. So local coins have had an incredible history and obviously the reason why people went away from local coins to central bank is because some of the private guys started abusing the system and generating tokens without control. But central banks never do. Well, central banks are a different entity because they have the backing of the full sovereign state behind them, which is a totally different thing. I'm not saying that they have been holding back, but the situation in the US before the central bank was created was huge numbers of private tokens and people were, you know, banks would bust left and right. You know, in this case, the whole country of the United States have to go bust before the token becomes.  But anyway, just to back up a little bit. We are the capital markets sig. So obviously we are interested in all kinds of tokens, not just not just CBDC, because we are interested in creating a digital capital market, which means both the asset side which will be the tokens for these kind of things and the payment side. And this is what money and others have been working tirelessly to join these two aspects, meaning how do you create a token, have it in the marketplace, and then pay for it.  So in order to go towards the safest alternative, which is a central bank digital currency would be the, you know, that would be the ultimate goal of a payment rail. So in that wider context, all of these efforts, including climate tokens are very essential parts of the puzzle for us. And to tell you the truth, many of these things of the properties have already been done in the TTF, for example, the from to date, the metadata manifest, you know, the IDs, we have to talk about them because I my conception is that they should be somehow linked to the legal entity and the identifier which is global setup for legal entities. So, you know, many, many of those issues have already been solved. So I have a feeling that once we start talking in earnest about all of these, and also the properties like retire versus burn, and how the e-tiler itself should be modeled the changes. You know, we'll talk about those. So in that context, you know, I would like to ask other people about what we should be doing in the next year or so. I mean, I welcome your input, of course. See, I mean, I don't even know how to pronounce your name. And various people say sigh or see. So, you know, I'm just going by my gut, but I would like to ask you how to pronounce that name. And then we go down the list and take input from other people, including money who has proposed something else. And people like Tom who had been in this business for a long time in the East and bringing up Gordon Chen. I mean, I'm in touch with him. He sent me his paper, maybe because you talked about this particular group, and we are in contact. And it's definitely the CBDC, one of the aims is for direct payment from the central bank to user accounts and the setting up of such accounts in central banks. I mean, that's a controversial topic, but it's going towards that. Plus, there's a great interest in climate change from, you know, the change in administration that is coming along. And that would kickstart things here in the US. Hopefully we'll rejoin the global community in terms of the Paris Agreement and so on. Anyway, so I think you should say what your aim should be for the next, you know, for this group. And obviously we want to work with you. We want to work with other groups. SIGs to promote and to work on real solutions. So please go ahead. I see. Sure. Okay, so yeah, first of all, my name is pronounced usually sigh but a good portion of the time see as well. And both are fine with me. So, in terms of what we're working on, yeah, the primary thing that we're going to be working on is making this net emissions network. And then building some applications on top of it. So for example, people can do virtual renewable energy by pulling together to buy into a community renewable energy project they could offset their transportation emissions together. I think I'm thinking about creating a distributor autonomous organization to go with these kinds of tokens so that people could make collective decisions together. So, I think where that could be beneficial is in terms of our linkages, then creating the interface and maybe even some of the applications that could then be used to make a real or a crypto currency, a stable coin that Manny's mentioned or something based on the E Thaler CBDC and maybe even the climate tokens could be linked to some kind of a currency in something. So those that's a little bit longer term off but I think because we're going to work with a lot of similar concepts and even some of your code base to start with that there will be good linkages between what we do and you do. Excuse me. So, one thing I, you know, coming back to your other point of the different currencies I think, you know, you're absolutely right there used to be a lot of regional currencies local bank currencies. Eventually they got consolidated into the central bank currencies. But I, I wonder if we're actually going back on that a little bit because just like the internet has really decentralized a lot of fields you know it's decentralized obviously the media and information fields. We could also have a decentralizing effect on currency so that 20 years from now instead of having most of us having all of our basically quote unquote money in the form of a central currency issued by the central bank of our country. We're not having a wallet that has some of our country central bank digital currency, but then some other countries currency, perhaps leftover from a trip or vacation or sent to us by a friend or family, and then a variety of currency like tokens, for example, that are entitled us to use an offset. Let's take trips on Uber or Lyft or, or flights or, you know, just a lot of different things instead of just converting everything back to one central currency and then re converting it into all these things that we use. So I think that's, that's something I've read about and it sounds not implausible and if that's the case then there could be a lot of applications of people wanting to issue currencies from various types of activities and redeeming them for other activities and, of which, I think your E-failer could be a very exciting sort of central piece of those. So that's, that's kind of a long term thing I've been thinking about. I mean, it's certainly happening today because you have loyalty points you have things which are local and in fact I'm a big proponent of local currency movement. In fact, I'm working with some people for doing for basically creating local currency for doing, you know, farming. You know, like community agriculture and then buying into a community program, which is very difficult now these days because you have to sell that and then you have to go and collect the produce every day. You're given so many baskets of produce. I don't know whether you're familiar with this sort of concept but with that, you know, once you have a tradeable currency then you don't have to buy something that, you know, like on the whole then you can say, okay, I'm going to invest in this currency and it's not being issued by one farmer by 20 farmers so you're not locked into one farmer and nor are the people locked into buying everything from that one farmer they can start. So this I've already started looking into for certain areas. So anyway, I mean, to not to belabor the point, I completely agree with that that there was going to be multiple local currencies and already there are, I mean, you know, if you think about your commercial bank deposits, they are nothing but sort of a local currency in a sense that the bank is holding your deposit, and you can only spend it in places where that bank network extends, unless you send a check, which then gets going goes through a whole series of operations in order to get converted to the to that bank liability being transferred to the other bank through again through central bank reserve accounts. I mean, so that's the key is, you know, all these things exist now, and as long as people can keep them going and it gets sort of honored by others then it's great. And I think it's an exciting time for for for all of this stuff. I mean definitely the decentralization is increasing. And I want to go through our member list with the participants who are there right now, and talk about, you know what their comments have been about things that are going on. And what are the things that went on this year and what's going to go on next year. I'll start with Alfonso. Hi, be pain. Thank you. I'm new to this group. Okay, I've been with you and the ID working group. And I'm here because I'm part of psi or see Chen group, and with Martin Wednesday. I'm a climate action and accounting. Okay, so I wouldn't be able to comment on this group. But what you both said you and psi about local currencies, which is something I've been into in the previous reincarnation. Local currencies that are not for community to graphical communities which that was the origin of local currencies, but communities of interest communities of values. And that's what side is opening up for the climate area. And that local currencies with the ether to me, it would be of interest, but I am a new be here. All right, Andrew. If you want to, you don't if you don't want to say anything that's fine, but please. Hi there. Thanks. I didn't find my mute button. Yeah, just I was recently part of our first citizens bank for a year and a half previously was part of the start of hyper ledger about four or five years ago when I was at Cisco. Taking a break, just jumping back in and seeing what's going on and really excited about all the new things going on here. And I have just kind of thinking about sort of non fungible assets and I've been on music licensing as a side project for a bit and it'd be interesting to sort of tokenize some of the royalty rights of music musicians and that sort of thing so the ethaler seems like interesting solution to that. And this whole push for the climate emissions is fantastic. I could definitely see some links with folks using sort of like the Tesla batteries for their houses and then reselling electricity back from the grid and you know each of them getting individual tokens, or you know communities of them getting a special tokenized incentives. So yeah that's my thoughts just throwing those out there and happy to be a part of the group. Thank you Bobby. Hi yeah I think it's fabulous that this ethaler project is getting traction in both of the different. Ziggs, I think that's amazing. I have since we started started to go to the labs to read about the ethaler project to learn more about it. I also think that the carbon emissions tokens are going to change the way you know the world operates and I hope that I can be a part of getting that out there and working in the future. Since you're going to go away, you probably can say a couple of words. Yes hi hi everyone. So, I mean, I guess this has been a very interesting year. There's been a lot of developments on on the ethaler so I'm glad to see that that's working and interesting for everyone. In regards to the capital market side. I've said this on a few occasions before. Given my background, I get lost sometimes on the technical stuff, but it's been good to trying to understand and learn from you guys, all of the presentations and the materials that have been prepared across the different, the different meetings. Thank you. Thanks for being the, you know, the vice chair, and I have to announce that Natalia told me that she's starting on a venture and, and hence we'll not have time to do to be the vice chair anymore so we'll have open elections for both chair and vice chair I don't know if people want to volunteer but already somebody has volunteered for the vice chair. So if there are more people then we'll have elections. Thank you. Then we go through Jagga. I'm just following you guys in this area of tokens and all these things are being located in India. We don't have any much exposure to these kind of areas. So I'm gaining knowledge through you guys. Thanks. Jagga is being modest. He coded a lot of the ITALA project, and he is one of the guys who contributed a lot to the project. So, you know, we have to thank him for the way in which especially the Java wallet and everything else and the interactions. And of course him and Mani did most of the coding with some input from me. So I have to be to recognize Jagga in this context. Kumara Vail. Mani's input is made all the coding. His input was quite valuable. Mani was the lead. Thanks again. So Kumara Vail, I guess it's having difficulty finding his mute button. In the meantime, Mani, could you opine on all this stuff? Before this is Tom is there. Maybe you can take input from Tom. Tom and Karen are the ones who are left. Yeah, I had a question actually for Sai. Can you share a little bit more about what the Climate Action SIG did in that collabathon and what was the output of it? Is there some, I know that there was the SIG led like a workshop or something or some sort of working group there. And what came out of that? The channel is, data is available as a link from our agenda and of course he can tell you more. Sure. There is a video and I'll post it as a link on your wiki page of what we talked about that basically we made a presentation about what the different groups at the climate SIG are working on. My little groups working on climate accounting, there's a group working on standards and there's a group working on consumer disclosure. And then we had an open forum with some of the interested people about exactly what we're doing. There was a lot of interest in business models and how to create products around what we're doing. So we had some initial discussions on that and a couple of developers contributed some help in terms of deploying the application and testing some of it and also working through the trust ID and security and identity and security for a network like ours. So there were some developer assistants that we got out of it. I think overall the whole collaboration has a lot of different topics, which many of which are pretty far from each other and so I'm hoping that over time, you know, things would tie together more as applications are built and available for people to have a point of reference. Thank you. Would you want to say something? Yeah, Vipin, you know me. I have a lot to say. But yeah, for people who don't know me, I was involved with Hyperledger a couple of years ago because I was working at IBM at the time, and then spent a couple of years at R3 working on Korda and was actually based in Asia, working on a number of areas in mostly around trade finance but also capital markets and tokenization digital assets, and then also did recently a stint with SDX which is the Swiss digital exchange in Europe. So, all of this, of course, is very interesting both the, from the carbon emissions which is an energy neutrality, which I think has been one of the interesting use cases for tokenization and there've been a number of projects over the past couple years around this. So it's good to see that size group is actually I think making more progress than other folks have. More importantly, perhaps in the capital market space. I can tell you that that there are there's some interesting approaches being taken towards dividing up investments to make markets more accessible for investors and not tokenizing things such as commercial loans for green projects, for example, so if I want to do funding for a new energy grid in, particularly in I think in Asia and developing countries but this might also be big in the EU, and we'll see about the US. For example, normally this was only accessible to investors who were coming in at very high levels, say $50 million or $100 million in terms of building out the loans or structuring the loans. But by creating tokenized versions of these loans you can suddenly drop that investment level to a million or less and then suddenly you make these markets much more accessible for much smaller investors and then also from the perspective of assembling investments and spreading my risk I can put together baskets of investments across all sorts of different, or I should say portfolios across all sorts of different investments that I've all been tokenized to various degrees. And that's the, and I know about this just again because I heard about this in regards specifically to green investing, because that kind of infrastructure tends to be expensive. This is a way to provide some more accessibility to those markets for investors and also from a bank's perspective, allows them by tokenizing those loans they can remove some of that from their books. So it kind of becomes a win win from both sides so that's why when you look at the tokenization of these assets and digitization of assets in general. I always have to go back to that question of okay, what makes what actually makes sense, because, you know, people are basically tokenizing everything these days, you know, I can tokenize my mother for example, seller on an open market but what actually makes sense to tokenize and what are the business conditions that warrant that so I think you're going to see a lot of attention being paid to that and then also the financial market infrastructures that will support this. There are different aspects to it that are different from traditional marketplaces in terms of custodianship in terms of settlement post trade settlement activities things like that. So, yeah, I mean this is where it could be interesting to see where the group can possibly take this. And of course CBDC is the big elephant in the room but I'll leave that for another day. Thank you, Tom. One is wanting to do talk about especially the post trade stuff and the lifecycle trade, which we are releasing a paper on CBDC soon, which will have those kind of things integrated into the into our thought process, and also the proposal that we are making on that particular topic. Yeah, again, thanks everyone it's it's quite exciting to know that, you know, whatever we have contributed with inputs from within and others in this group helped us build, or at least an initial prototype version of each other and I'm glad to see now that's being taken up for other and that's what gives us in even more interest in adding more to the open source contribution so as we've been pointed out, you know, we're working a lot of work on post trade infrastructure automation in the capital markets, which is, you know, it's a whole big area to actually bring blockchain about that's more on the commercial side of things. But you know from from a capital markets, SIG perspective, as we discussed, more collaboration on common token definitions beyond the TTF that will be of interest to us, because we are while we are developing things on the capital market side for other other types of tokens. There are other functions like token administrator transfer agents, these roles must be, you know, it's better that be standardized or codify this, you know, the functional behaviors of this. Again, help adopt these tokens much faster because it's one thing to just, you know, mint and burn and transfer tokens, but how do you really apply considering the fact that you have KYC and AML requirements. It will be very useful if we can come up with some sort of a specification for these, these roles regarding token administration and transfer agent. Separately, you know, we, we are exploring about confidential computing was another big hot topic. It ranges everything from is bilateral to multilateral settlements and index calculation today in capital market everything the data has to be all gathered from one central party who does then, you know, calculate the index and then redistribute back to all those. And in the process this the intermediary takes a big, you know, value out of it. But this can make it even more decentralized if we can come up with a confidential computing model whereby all the interested parties can contribute to a price or to an index and then system will come to the index and no one has to pay for it. So it will be an interesting open source project that just one, one aspect of it you can, we can talk about whole host of things and every industry where confidential computing can be used, but we will start somewhere. We are looking at the, you know, we're still looking at some kind of we need an open source underlying API is there are some from Google and Microsoft. Since is the very nascent industry at this point, we want to be able to pick up some some open source platform based on which we can build that and contribute back to hyper legend. That's my thoughts. Thank you, my beautiful. So we, you know, we basically welcome all input. That is the whole purpose of having the sick. And we also want to work across things. We started talking about that. I'll be giving a presentation on the public sector say on CBDCs, it'll be pretty going up from basic basics. What I know, I'll be able to share. And that's, you know, other comments by anybody else. You're welcome. You know, we welcome comments and we welcome collaboration. When is that presentation. Friday at 10am Eastern on the public sector thing. It is going to be called a rationale design choices and challenges of CBDCs, but it's going to be a pretty, you know, if you know about CBDCs already. It won't be that useful, but I try to go from first principles. Anything else before we close and, of course, we have to say thanksy as the animator of this whole, you know, retrospective, perspective. And also, we need good presentations. So if anybody has ideas about that or willing to present, then we will welcome that, especially in a thematic sort of way, maybe we should have quarterly themes or something where we can direct the energy of the group into these important questions. That's my thought and all, you know, please go ahead and make any closing remarks because we are 1057. I guess we have exhausted the topics with today. Thanks for attending. And we will get together two weeks from now. Maybe because as we come closer to the holidays, we will probably postpone these meetings, or at least cancel the meetings this month and start again with a fresh thought process and everything next year. Thank you. Thank you. Happy new year. Happy new year if we don't see each other. Yeah, happy new year. Let's have a good one.