FILME 1 AUSSICHT

FILME 1 AUSSICHT

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then next we'll we'll come back to  lecture two that has some new additions so let me share screens here um uh can you see the screen now with the uh uh page two yes met321622 okay thank you so as i we have some people coming in from the second  university so i will keep admitting those so as i said this lecture is actually  in your list is uh the the third week   and uh next week we'll switch that around  but so today we'll be looking at the   thermochemical water splitting to produce the  green hydrogen from concentrated solar systems and so as the um we use different colors to  distinguish how the chemical hydrogen is produced   we use green if it's produced from  renewable energy we use gray if it's   safe made from fossil fuels if we use steam  methane reforming to reform the methane ch4   into hydrogen so as a result we have some carbon  dioxide emissions if we capture the carbon   dioxide in the carbon capture and storage system  we would call that blue hydrogen so as we use   these different colors to distinguish  the process how it's being produced   and so in the green hydrogen from renewable  energy the opportunity here is if we could go to   a process instead of electrolysis  using electricity say from the solar   photovoltaic energy or from wind energy  electricity we go through a thermochemical   reaction uh to produce the water splitting  and produce hydrogen and oxygen from water and within that that's our opportunities so if we were looking at  the theoretical efficiencies   of of different technologies this uh solar  power power concept that's like on our textbook   we have the opportunities to  get quite high efficiencies   if we go down to the actual efficiencies of  photovoltaic with electrolysis it may be quite low   but it's a direct energy conversion less equipment  and so we look at the total cost of ownership of   the system and so what we want to do is to in this  project is do the comparison of the solar thermal   to the solar photovoltaic electrolysis and  producing the green hydrogen and uh i'm going to push up just a little bit so we there  we go so our opportunities are the   the pdb electrolysis if we had certain assumptions  it could be higher but some of those assumptions   aren't realistic you know are impossible to  get to so we want to sort of go through the   exercise of looking at the options finding out  which one and for a specific location in peru um so we have the sun it we concentrate we  might be able to achieve a concentration   with the power tower to a factor of a thousand  times what the sun is so we've used that   terminology as a thousand suns so instead  of this a parabolic uh trough focusing along   along the line like we have on the top kenoi  and the in the solar lab we would see something   with the potential of going uh thanks  yes dr ramos excuse me i think that   right now you are using the slide number three or  four but we are seeing only slides and number two   okay so okay thank you so i'll stop sharing  go back out to uh to share again um and with the introduction to the  concentrated solar with the efficiencies just yes okay so what we were talking is in  the uh the concentrated solar power two-step   thermochemical we have efficiencies of 72 this  solar pv electrolysis may be higher but some   of the assumptions are impossible and so what  we're doing is hoping that we can come up with a   concentrating solar power it goes through  a solar thermal chemical process to produce   the green hydrogen uh and what we'd like that  be without using a fossil fuel so some of the   earlier concepts we'll talk about uh combine that  carbon capture so this is a slide where the solar   concentrator with a concentrating with a tower  we can achieve a a equivalent of a thousand suns   focus on an area and uh next time i'm gonna  show a movie of sandia national laboratories   their experimental uh solar power power  what they can go through those experiments   one of the concepts is to in the  receiver is a circulate of molten salt   and the the molten salt can be at a high  enough temperature that matches the receiver   and if that high temperature then we can go  through and have superheated steam go through   a thermochemical process and produce the hydrogen  but the question is it what efficiency do we have   that so this was the company uh heliogen and they  have uh this technology and the question is here   if we look at the input to the reactor as part  of the concentrated solar receiver at the top   of the tower we see that it has the water as a  feed that then produces the hydrogen and oxygen   but we also see that it carries carbon dioxide  now the carbon dioxide in these cases may be   uh as part of uh the process that we're trying to  capture the carb the emissions from something else   and using that in a way that we've captured  and stored so what we end up having is two   of fuels as output hydrogen and carbon  monoxide the oxygen is the excess from   splitting the water and there's a  purge gas because we might want to keep   the carbon monoxide from reacting in this  combination so this is a concept but maybe   that new concept has some also limitations and  have some risk so one of the challenges i want   for you to consider in this semester project is  look at this initial information and begin to go   on a particular direction you might toss something  out say sorry to do a house of quality check   pros and cons and then find out which one you're  you're migrating to so here's the heliogen tower   it's a smaller almost a demonstration size is that  a mine in uh california uh a boron mine and uh   this system then is to reach potential on the  road map if you will to eventually get the   1500 degrees celsius right now they're at  the 1000 degrees celsius that gives us higher   conditions than we've had before now if we were  to think of it as a heat engine we the the carnal   engine the heat engine is we put heat in we get  to work out and we have waste heat that we discard   and so the we can define the overall  efficiency so within the dotted line we   have the thermodynamic heat uh thermochemical  cycle and we could have uh the hydrogen um   being produced and the fuel cell when we use that  hydrogen recombines it and produces electricity   which is it provides our work so um what this  concept of putting the dotted lines and putting   the two components together allows us to uh  view it what is it up you know what is the top   efficiency we can get if it's the heat  engine combined together um so the the   uh so what they're saying is the chemical  species are in a closed loop in this definition   of the carnot cycle now our purpose is also uh  maybe the fuel cell is on the truck and we're   producing hydrogen is that maybe we have another  use of the hydrogen so that during the night time   we've taken the thermal energy here produced  and stored the hydrogen and then we generate   hydrogen generate the electricity from using the  fuel cell as a uh sort of like a reversible uh   battery so we're generating that electricity  so in in our applications we want to have two   two in uses of the hydrogen want to  generate the electricity in night time   and two to fuel the trucks with the hydrogen so the maximum heat to work efficiency through the  carnot heat engine remember in thermodynamics we   break it down into heat engines and heat  pumps which way is it the circulating so the   work to heat is proportional to the temperature  in absolute the temperature difference at the hot   side divided by the absolute temperature of the  heat so that allows us to do a calculation and   maybe this is what we might see is we  have a maximum possible efficiency as a   function of the temperature if t naught the  reference of the cold temperature is fixed   and then what's the um sort of the figure of merit  if if we're operating with a figure of merit of 65   what would that curve look like in other words if  carnot's 100 percent figure of merit what is 65   and that shows us at about a thousand degrees is  beginning to level off so we have this opportunity   is maybe if we're at 75 figure of merit 75  percent of cardinal efficiency it doesn't level   off at a thousand degrees it begins to level  off at a higher temperature so those are those   opportunities which thermo thermochemical a  water splitting process do we go for so that   maybe we can if we can't get to the higher  temperature we can get the higher efficiency   if we had a lower figure of merit we might not  get much return and it's pretty well flattened out   or maybe actually begin to drop off at a higher  temperature because we have more losses so that   concept of the heat engine when we combine the  fuel cell with the thermochemical reactor together   provides us that opportunity let's do it see  it in a bit and i don't see it let me know okay so here's one where we use um metal  oxides applied to the thermochemical   water splitting for hydrogen production using  concentrated solar energy and uh it's a fairly   recent 2019 and so what this does is it has a tin  oxide that goes in as the reactor and so we we   we have a chemical loop if we will in that  thermochemical reaction so instead of having   the electrodes having the catalyst and the  anode and the cathode with platinum on it   what we're doing is we're putting a a compound  a chemical compound into the reactor at the high   temperature and it helps that dissociation and  from that it allows this combination of the use of   the reproduction of the uh power if you will if we  store the hydrogen and then here we can go through   this is from the paper so we can go through and  see the efficiencies of the energy efficiency   of that cycle is not at that 80 percent but at  a lower value but it's still higher than the   than the pure uh pv uh electrolysis process  uh unless we take uh a combined effects so um   here are some of the other uh reactions  of a single stage water decomposition we   just put enough heat it dissociates the water  into hydrogen and oxygen but the temperature   has to be over 2 500 degrees celsius we're  nowhere near getting to those temperatures yet   we would need probably 10 000 sun concentration to  start approaching that as a pathway if our limit   the focus is at a thousand suns then  probably 1500 celsius is our upper limit   so we can't quite get to the single stage  decomposition without some other energy input   a multi-stage using copper and chlorine through  a splitting process allows it lower temperatures   so at the 400-500 degrees celsius we could  go through that but now that we're 30 years   into the development of the concentrated  solar powers we can go beyond those cycles   maybe until the the heliogen we were peeking  out at something like 800 degrees celsius   so let's look at what some  of those might have been   so uh you can see over here if we were up at  1450 celsius we can do a volatile metal oxide   and if we have a non-volatile  uh the metal oxides we have   temperatures that may go from ranges from 1800  celsius down into that 850. so the sulfuric acid   is one uh reaction that we could have in the power  power so basically what we're doing is looking for   chemical reactions that may require two steps that  is two sets of equations that occur sequentially now like the electrolysis process the and on the  cathode get consumed in terms of their reacting   elements the platinum so in these uh sulfuric  acid if it's very strong we're going to have   reactions with our metal and we have a lifetime  limitation so we might have a reaction here   but what's its life so when  we do the total cost of   of ownership if the life is shortened but we get  good efficiency that may not solve our problem so one of the concepts was a two steps   that go high temperature and use an endothermic  metal oxide reduction to release the action   lower temperature and exothermic reaction of water  with the metal so um endothermic is what again exothermic it releases in endothermic is  cooler okay so if it's cooling at the uh   at the high temperature then we don't  exceed the temperature limits if it's   releasing at a dollar temperature we have  some margins to to work with so and and so the the the opportunities is to look  at a list like this and try to think   which one do we want to do we could look at those  technologies see what the state of the art is   and and choose one or uh compare them so most of the low temperature cycles either  employ intermediates to for oxidation that   that are complicating the cycle chemistry  or use electrolysis to release the hydrogen   restore the original oxidation so at this point  one approach would be could we have a reversible solid oxide fuel cell that in the reverse reaction  is an electrolysis process and the other it   becomes the fuel cell so instead of having two  devices the reactor and the the fuel cell we   have one device that depends on the direction of  the uh demand are we needing to store the energy   in hydrogen are we using the hydrogen to generate  the electricity at nighttime so at that point is   the opportunity to say maybe that's our goal  we take the chemistry opportunities have been   been worked on for 20 or 30 years and then say  what we'd really like to do is the oxide being   a solid oxide fuel cell but make it work backwards  so it's a reversible solid oxide fuel cell when   it does in the reverse it's an electrolyzing  process which is what we're talking about and so   the sulfuric acid is 850 we can go over a thousand  now what could it what would be those reactions so the question is what are the opportunities  for the thermochemical water splitting for mining what's the big energy hog in the mining  operation the open pit mine operation so we you know unlocking the power of the sunlight  for the mining industry but what would it be the equipment right so we could have the electric  the requirements for the electrical equipment   that maybe changes from diesel engine  mechanical drive with gearboxes   to electrifying that industry using electric  motors and then if the motor is on a vehicle   that needs to extend its range of the batteries  recharge the batteries on board so if we have   a fuel cell instead of stationary if we have  another fuel cell on the truck the mining truck   and we run the batteries and we have charging as  it comes up the the out of the pit with trolleys   charging overhead cables with high voltage but  we still need more power we don't want to have   to stop the truck and recharge that would  allow the hydrogen that's generated from   the the green hydrogen from the uh concentrated  solar power system to be filled the hydrogen tank   on the truck the fuel cell on board recharges at  a constant rate and then the the electric motor   pulls the power out of the battery on demand  so we're going downhill we can use regenerative   braking to recharge the batteries when we're at  the bottom and we start up the hill we have one   load as we roll around the corner we might have a  different load as we go through that dry cycle at   the top of the pit then we have to go with we're  going to unload the truck into the crushers so   we have a different now we're going horizontal we  have a different load so the battery and electric   motor respond to the demand what speed what grade  things like that but the fuel cell operates at a   constant sort of like a not a trickle charging but  it's charging at a constant rate so we can extend   the life of the fuel so it's not having to respond  back and forth through temperature and and and uh   because there's if the fuel cell is the expensive  part that we're trying to extend the life   so let's let's go through another one so um so the  example here with the photograph was pio rio tinto   which is an anglo-australian uh multinational  second largest metal and mining company   and with the heliogen is exploring deploying their  heligen solar power power at the borate mines in   california the pictures that you saw  earlier and so they're looking at uh   controlling four thousand forty thousand  uh mirrors to focus on the the tower and   capture that energy so we have a major mining  company exploring the concentrating and uh   and also the potential then if they can do that  would be add the next step with with hydrogen   now i looked last night and i found out that  cummins had received two awards from department   of energy uh last cycle funding cycles from an  annual cycle and they were for smaller scale or   mid-scale solid oxide fuels reversible fuel  cells that is the fuel cell in reverse could   be generating the hydrogen when you need to and  now you compress the hydrogen when you need the   electricity you can run it through the fuel  cell or you can fuel the tank on the truck and   use the fuel cell on board to recharge the battery  so um cummins is a diesel engine manufacturer   they supply to commercial trucks maybe not at  the scale of the of the caterpillar trucks and uh one of our students or two i guess a  couple of people at caterpillar but   uh wants to show me a picture of where they  you know the the hall truck being assembled   during the internship so now let's look  at the the question then is um dr ramos   yes uh i'm going to increase right here so i have  more people um question for you do you see the uh   group of people in the uh on your  screen or do you see a slide okay um johnny do you see the black screen with the  boom participants hi john uh i can't hardly see it   okay um one stream and what i'm gonna do  is rotate the camera okay and that is well they're only seeing the slide but in this picture  of me they're seeing the that so the layering it   is not available for them but it does allow  us at least for here and indirectly from this   computer cam this opportunity uh so um  dr newey this what we found was that   cummins that's an indiana company that has  uh leadership uh by purdue alums engineering   from the president to vice president and  so on and what we would like to to do is   give the students this opportunity to  evaluate uh from a simplistic approach   what is the how do we meet the  demand for mining in peru say for the   the falcini lithium mine in hard rock and and puno  and what that would be is uh what we'll do on next   friday is to show some examples of the solar data  look at the solar technology the basis of that   and come up with basically a rule of thumb and the  rule of thumb uh as a prelude what you'll see next   time is that if we look at the map of the world of  the solar potentials and then the scale it will be   it will be a thermal map so you'll  see different colors for different   values but on the on the bottom scale  it'll show the amount of kilowatt hours   per square meter per day or a second scale will  be the number of megawatt hours per square meter   per year and the highest value in the world is  in peru so you see a color bar and in the in the   light pink is the maximum value if we have  a concentration of 1000 sun with the power   that translates to 2.7 gigawatts hours gigawatt  hours per square meter per year so if we needed   4 000 hours of energies during the night  time out of the 8 600 that would say we need   4 000 square meters to produce a theoretical  limit of about 2 gigawatts of constant power so what we want to do without getting into all the  details of of the tracking system and the location   and the time of day and the day of  the year is to look at average values   and use that as sort of our rule of thumb to begin  to make decisions on which what's the potential   and then which the efficiency  out of that 2.7 gigawatts   per uh square meter gigawatt  hours per square meter   if we had an efficiency maybe it's 2.7 might  multiply by 0.7 then that gets 0.7 times the 2.6   gigawatt 2.7 gigawatts so we can do that then  we look at what the uh what the demand might be   what's the split between hydrogen for electric  generation in the night time and what's the split   for the hydrogen for recharging uh the batteries  on the on the vehicle and we could we could have   that sort of parametrically and say okay ten  percent for the vehicles and ninety percent   for the uh they you know the nighttime  electricity all the way to ninety percent uh hydrogen for the truck and ten percent  for the local electric grid the microgrid okay so let's do an analogy  let's say you have a minivan   and it's a all-wheel drive it's not four-wheel  drive because it's not fixed it's all-wheel drive   and so originally when chrysler had their mini  drive a mini event their drive was all the way   to 90 percent front wheel and 10 percent real  and reversing then they found out that they   didn't need to go that wide of a range maybe 65  35 would be a good mix and then in reverse to the   other combination for stability for controls  turns out the abs braking system interacted   with that variable load of the transmission put  the brakes on a lot of the braking is in the front   wheel and the and the powers on the front wheels  so you had this high frequency feedback mechanism   so they had to increase the weight of the car to  make the abs they took the abs off then they had   to put it back in and so it took them at two  years to figure that out so if we're operating   a mine maybe that demand changes as the demand  scales up to the demand for production of lithium   maybe initially we have 10 trucks and  at full capacity we need 16 trucks   running all the time so the demand over the  life of the cycle of the mine changes slowly   but maybe when we add up five new trucks or  six new trucks it's a big change from 10 to 16   it'll be a big change and so we  would need to have that design   so from from the the teams then this opportunity  is sort of carving out what is your niche in the   bigger picture you're not don't try to solve the  whole thing find out where part what component   last semester we tried to do it where by by  selection different teams did different things   and then merge those together and that's a lot  harder to do because you're relying on a lot   of other people to give the information  and if you're at the end of the chain   you have a time crunch at the end of  the semester so what we'll try this time   is to let you independently in your small groups  choose what topic may be of interest to you   and what topic you feel  comfortable managing working on   and then we'll have sort of the mid semester  reports coming in to sort of compare what's   going on and we have about four weeks into  two more weeks of lectures like this on friday   then stu is going to give a lecture more from  organization leadership and other aspects that   we want to get you trained on and that is how  do teams develop how do you um resolve conflicts   how do you communicate what's your world view  of this problem like this the heliogen with the   mine in california it's also working with uh  rio tinto which is this large mining company   well the smaller mining company in peru  is working with say caterpillar which   has presence all over the world but maybe  caterpillar should be talking with cummins maybe one of the things is you reach  out you'll watch the movie next week   and you'll say okay i need to reach out to  sandia national laboratories in albuquerque   new mexico and find out what are the what are  the plans for the next two years on testing   with this research facilities this their solar  power research labs we can always look at the   reports they've already done but what we don't  have is what's planned for the next two years   they don't usually publish that okay so that's  where the communications is reaching out trying   to get information so that's a skill that you need  to develop to follow best practice learning how to   get people to share information with you  without necessarily having to pay them   for those services okay can you you know sometimes  it's just a communication sometimes it starts with   an email and follow up they don't answer the  email you make telephone calls they don't answer   or they don't give you information they say  they're busy or whatever you do another follow   email and so you go that it's sort of a campaign  it's a campaign to get to the person that gets the   information you know one time i remember  doing something like this and what i did   i'm looking for a summer internship  also they wanted to talk with me so i said well what are you doing on this area   and then i went to argonne national laboratory  for two weeks so they paid me to do that and   but i got the information before i went so it  was one strategy work it was like a home run   i got the summer job for two weeks  that i wanted and i got the information so it works sometimes that way i did that once and  another facilities and went for the whole summer   and i thought i had a job and then there  was a change in administration and they   basically cut the funding for  the whole program so i spent a   whole summer working on something  that didn't get followed up on it it was on concentrated solar it was a heat  engine for 10 kilowatt with a parabolic dish   great idea and we had face change thermal storage  in the dish at the receiver and there were some   problems because it ex the metal expands and  contracts it pulls away so it was a really good   opportunity but there was a change in policy at  the government and the program was cancelled so   that's where this communications is sometimes  it's timely sometimes it's important so next week   there's a conference on  hydrogen in the mining industry   on the i think sixth seventh and eighth or  something like that so there's an online seminar   with eight or so talks about it okay so that  this is current information i mean it's out there   and the question is how do we do that now another  thing that i'd like to share with you coming up in   in uh next month in october in glasgow scotland  we're going to have the so-called cop26 the 26th   climate change action committee prior to  that there's some leading companies that   already made the decision to change  the race to zero their race to zero instead of 2050 the industry is  saying we need to do it by 2040.

and think about it if you're going to invest a  lot of money and you can't commercialize it for   another 30 years whoever's the the leadership  in that company have long retired and their   investment has been showing returns so if they  think the risk is pretty low compared to something   of risk not doing it they push the due date up  earlier so their returns can come in earlier   instead of waiting for the government to make  a policy so this is one case where the industry   begins to take leadership as opposed to waiting  for the policy to allow them to to migrate over and so think of this this semester  project is working on on a big   perspective now i might have mentioned industry  4.0 and we're looking at in our degree program   figuring out how to make a learning smart  learning factory for meps in the new building so it'd actually be a production operation that  you take your classes in the production operation   as opposed to the laboratory but the europeans are  already working on industry 5.0 in industry 5.0   it want it has the the centric around the  individual as opposed to the large industry   the factory and two it has energy efficiency as  a driver so in europe they're leapfrogging over   they haven't gotten to industry 4.0 but they're  leapfrogging over and said we need to be at five  

we got to start now because some of the  things we're going to digitize in for to do that it works best if we also looked at the  power structure okay so in indianapolis uh today   they announced uh uh thinking of facilities to  test large-scale uh electric battery packs for   larger vehicles not for the passenger vehicles but  for trucks so they're taking obsolete facilities   and leapfrogging and over and jumping into  test facilities for the next generation   so again try to think of this this uh  project now you have the collaborators in   peru and the peruvians have the collaborators here  at purdue in indiana so we have a major presence   at caterpillar and that presence has become  a little more influential than it was say 10   years ago we have cummins who's become a major  player in the hydrogen technology but still has   a lot embedded into the combustion they're also  looking at that combustion technology and say   if we have a solid oxide fuel cell that looks like  an engine it's running as hot as the engine did   and the all of the metering and and  things like that are similar we can   take the information we have the knowledge we have  the manufacturing technologies and apply it is   cross-cutting the technology's cut over from the  diesel engine over to the solid oxide fuel cell   we still have emissions we have to wait we still  have to have life cycle we want it to last a long   time compared to the pan fuel cells and we want  high efficiencies we want the power we want the   torque whatever it's a combination of those so  as as you create teams one of the things that stu   reminded me to say is read your emails so if you  have a purdue email you have to start reading it   daily okay because somebody's going to email you  might text somebody but sometimes we call somebody   or text them but then you have an email why why  do we need the emails that the text can't provide i can send you maybe a 10 megabyte file   i can send an email invitation  to download a two gigabyte file okay so you use all the communications  and you start doing that okay obviously   with our peruvian partners we need to  start reaching out to them we have uh uh enzo for example has been involved with uh more  than at least one or two semesters two so for a   year he's been working with previous uh classes  and groups okay uh hector has done the same   dr uh now we ortiz and dr ramos we've  known each other a long time so we've   worked together so we've built that relationship  so one of the things on on three weeks from now   stu is going to give a presentation on the friday  on this leadership organization and also what are   some of the things that we need to look in the  future and that is multicultural intercultural so if if i talk with my engineering friends  at the caterpillar plant in uh lafayette   and i have the hr director living across from me  sometimes they talk about it on which side of the   is it the north and south no what's the what's the  reference to the caterpillar the front or the back okay if we go to wabash national it's the  south of the north plant or something okay   so you might have a different culture depending  on what part of the organization you're in   so one of the things we want to do is purdue has  developed and it's a required requirement in the   uh me 201 class it's a what they call portable  intercultural modules and you put it into space   so you essentially get credentialized going  through this training of that things and so what   we're going to do instead of thing is a ethnic  cultural or a national culture we can think of   it as a corporate culture and generalize that how  does what's the culture it comments versus what's   the culture of commons 20 years ago what's the  culture of caterpillar today versus what it was   20 years ago what is it going to be 20 years from  now so in your start of your career you're going   to have to be adaptive to those changes in culture  just think of what the pandemic has done for us   we've learned to use zoom and all these  other tools we also miss a lot of things   i hate wearing a mask i mean does anybody love  wearing a mask i don't i need it you know it's   like mitch is cheap so have you ever noticed his  cheeks or he has red uh rubbed cheeks on his face   so some of it i know i don't know if it's shaving  where he does or something but he gets this really   bad rash on his cheeks right here wearing a mask  but we've learned to to to adapt in some ways so in uh and we're not through it yet  right we still have to go forward   so on on tuesdays uh dr noe and dr ramos and some  other students meet at eight o'clock at night   on zoom because that was a time that nobody  seemed to have a conflict it wasn't a good   time it wasn't the right time but that's  the time that we have to work with okay   now in their case in peru you know the times  you know the for part of the semester where   it theirs is seven o'clock and another  time it'll be eight o'clock so there   they have to have an adaptive class if they meet  with us or we have to change so how do we do that i i have a presentation i was supposed to give  and and it was at three o'clock in the morning   on a friday and i was going for for 40 minutes  and i could go to sleep and then do that i'm   not going to drive to the campus i'll do it at  home and i'll wake everybody in the house up   you know there's a lot of things that that  made us to rethink about how we to do things   so in this class what i want you to do is work in  your teams interact we're going to change some of   the interact uh videos we're going to mix that up  a little bit okay so it'll be more what we think   of as professional development in your interact  as opposed to just you know getting somebody's   opinion they watch a video what do you think of  that so we're going to try to make the interact a   little bit of a professional development almost  like you're credentializing these skills okay   doctor uh or almost next week yes um i i have a  a new edition of lecture two for friday that uh   we'll do my apologies for for  not having that saved correctly   thank you very much professor yanchez thank you very much thank you very much

2021-09-10 12:14

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