Hello and welcome to NewsClick. I'm Paranjoy Guha Thakurtha and with me from London is Professor Maitri Shkhatak. He is a professor at the London School of Economics. He was educated at Presidency College in Kolkata also at the Delhi School of Economics and has a PhD from Harvard University and we're going to discuss inequalities of income and wealth in India at present. Thank you so much Professor Maitri Shkhatak for giving us your time. Let me start with a few points that you made in your recent article which appeared on the 18th of May in Forbes India where you pointed out that in the financial year which is over which got over on the 31st of March for the first time since the country became independent in 1947 India's economy shrank by about 8%. At the same time this was a period that saw stock market indices zooming. They went up by about 75%. For the first time in the history of India we had what would be described as a technical recession in American terms where in the months of April, May and June of 2020 the economy shrank by almost 24% and then in the next three months it shrank by another 12% and for the full year it's roughly about 8%. Even as this happened stock markets are booming and of course the number of billionaires US dollar billionaires have gone up from 102 to 140 with their combined wealth almost doubling to $596 billion US dollars. How do you explain this paradox? An economy in recession, stock markets booming, the number of billionaires going up. First of all thank you Ms. Gupta for inviting me. I follow your writings and your other presence in the media with great interest so it's a pleasure to be in your program. So I would say that first let's set a benchmark. Even in an ideal world with say no particular departure from say a competitive model of the economy that we economists like to teach in our textbooks right where even in a competitive and that way frictionless world there's no reason that we back each other so we should get that out of the way. So therefore logically it's possible even if something is not wrong that the GDP could go up and down and the stock market would not necessarily track that and the reason is the stock market has to do with allocation of wealth and the GDP has to do with current economic activity and as we know that the stock of wealth is something that has its own logic and how it's allocated and therefore it is quite possible that the current flow of economic activity may go up and down but the stock market will have its kind of own logic and secondly and relatively the stock market has to do with the future. So for example if you believe that you know two years from now there's going to be a big opportunity a big sort of boom happening then market could could be booming because capital flows in etc international conditions right so therefore capital can be parked from one country to another. Now I deliberately set the stage up with saying that logically there's nothing per say wrong with the stock market and the GDP flows to sort of you know not move in in in sync but having said that look at the extent of it I think that is what caught your attention and that's what kind of caught my attention as well and many others who are observing it and I think there are reasons to be worried about it in particular because essentially what has happened during the recession as we clearly saw in the case of informal sector workers migrant workers whose problems were made very visible the flow aspect of the economy where you know the everyday supply and demand in work and and people's needs they need to be sort of connected in a certain way serious strength and yet what has happened is certain types of activities certain things are being people are making super profits and therefore stocks of certain companies are going up because in a particular economy just to give an example that if you if you have extreme scarcity of something the stock price of that would go off the roofs right and certain people would make make huge profits out of it. So I would say for a number of reasons I you know as to so even though in an ideal world the GDP and stock markets there's no logical reason that they should flow with each other in India's case the extent of the discrepancy and you know I haven't done a quick cross-country comparison but there's nothing stopping us from actually looking at what is going on in other economies. I think that should worry us about the nature of markets here what entry barriers exist etc businesses are are doing extremely well stop here. So what you're saying Professor Mitrish Khattak is that essentially while we are not really living in an ideal world and why there is no need for the the stock markets to reflect the reality as far as the economy is concerned the the the discrepancies the dissonance the the divergence seems to be unduly large as far as India is concerned and if we look at what's happening now that India is in the midst of a second wave of the pandemic many are of the view that what the government had claimed of a so-called V shaped recovery some would say a U shaped recovery now that's going to materialize in fact there is a real and present danger that the economy will not only not revive but perhaps shrink in even as we are talking and the problem is that despite all the claims that are made by our political leaders about how we are you know our our GDP will double or whatever I mean and we're going to do very well India will become the so-called Vishwa Guru I'm using Prime Minister Narendra Modi's language the fact is India remains very very poor and you yourself have pointed it out in your article that whereas about India's population is roughly 17 percent of the world population a little under 18 percent of the world's population soon we will become the most populous country on the planet but about a fifth 20.17 percent according to the World Bank in 2017 one fifth of all the persons in the on the planet who are living in extreme poverty are living in India that is out of 689 million about 139 million so the reality is that India remains very poor India's economy is not growing is likely to continue to shrink at best grow at a very sluggish pace as we see concentration of income and wealth continuing to grow absolutely so in fact let me let me give you a little example which is to your earlier question but catalogs allow me to segue into you know issues that you threw up in this question so imagine you losing your job during the recession so your labor income flows will stop right yet if your house is in a particular neighborhood for others to your house could appreciate in in in terms of its value so therefore going back to you know I wish I had thought of that example when I was maybe expressing myself a little bit too sort of you know abstractly but coming to your question this question for the last few years in lots of my writings on the Indian economy I have expressed this frustration repeatedly and and and I will take another opportunity to express it here that first of all the GDP growth rate has somehow occupied the center stage of our discussions it's almost like a rhetorical victory of a certain ways of looking at the economy because see the GDP measurement as anybody who knows about national income accounting is very very uh what can you say not a it's an opaque process as activity by whichever method use etc and the informal sector all of these uh make it a matter of a fair bit of guesswork now that's fair enough we need indices and we need some measure of GDP that's not a problem but there are two fundamental problems of GDP uh center discussion and that relates directly to your question one is that because the GDP is a diffuse measure if in the entire country 99 percent of people actually have no change in their incomes but one percent of the population right experience astronomical growth in their incomes the GDP growth rate would still look pretty good and that is therefore it's a simple point anybody who kind of you know thinks about or works with these numbers would know this issue right that the GDP is not it's all it's saying on average India consistent with 99 percent of people experiencing no growth or even a deterioration and one percent experiencing astronomical growth in your article you have given some of these numbers I mean what you're saying in in lay terms is Mr Ambani and Mr Adani's income can grow it doesn't mean that this is the uh the the countries or the majority of the people of the country their incomes or their their wealth is growing now you have quoted from the world inequalities database compiled by people like professor Thomas Spaghetti and others where you really looked at both inequality of wealth and inequality of income I'll briefly summarize some of the points you made you've said that the top one percent of India's population had roughly 12 percent of the total wealth in the country in the three decades the 60s the 70s and the 80s 1961 to 91 and thereafter this proportion has gone up tremendously from 12 percent to 42.5 percent in 2020 and in this period if you look at the bottom half of the population the bottom 50 percent the share of the the wealth has come down from 11 and 12 roughly to a sharp fall of less than 3 2.8 percent and you find similar figures are there in when you look at the figures of income inequality where the top one percent of the population their their share of total income actually came down from 13 percent in 1961 to 7 percent in 1981 but then shot up to over a fifth to 21.7 percent in 2019 and the bottom half the bottom 50 percent of the population this number this proportion from hovering around 21 20 to 23 percent in the 60s 70s and and 1961 to 81 it then collapses to under 15 14.7 percent in 2019 in other words the so-called post liberalization period we see a sharp rise in inequalities of income and wealth even as the rate of growth of India's gross domestic product has continued has grown has in fact accelerated. Right so I would say this is the bit that one should worry about and that relates to your earlier question that what I said that yes we should know GDP growth rate as much as before visiting a country we need to look at its map it's all the local variation we to kind of a very snapshot aggregate bird's eye view so GDP growth or GDP measurement is helpful but relatedly it's a statistic that's reported in the in the in the piece that you quoted if you look at GDP how many times it has multiplied since the late 90s to now so just think about these two decades right late 90s to say 2019 or 20 up to which data is available the per capita GDP has multiplied many more times than rural agricultural wage rates right now given the number GDP per capita income between 98 and 2019 went up eight and a half times rural wages went up at only 5.4 times exactly thank you so thanks for those exact numbers I didn't want to say it without checking the exact numbers so this is the problem and an example I was giving earlier there's nothing wrong with growth and when growth opportunities arise some people will benefit more some people will not benefit so much this is also understood but it's the question about is that a rising tide that lifts all boats or is it a rising tide that systematically benefits some you know ocean liners whereas most of the other boats are struggling to stay afloat I think that is really the main question here so therefore I think going back to my reservations I'm sorry GDP growth rate or focus on it is we should focus on income growth there's nothing wrong with it but we should ask the question to paraphrase like what John Kenneth Galberts had written in a speech for president Kennedy ask not what the country can do for you ask what you can do for the country ask what the GDP growth rate has done for you lately okay you would question we can ask it ourselves as to how people you know in our families in our neighbor who's a benefited but everybody should be asking this question from the agricultural laborer to the industrial worker to the informal sector you know tradesperson everybody should ask that okay growth is fine I mean more opportunities you know more income that's all good but if the average growth is this why hasn't my wage growth has kept pace with it if the average growth is this why aren't employment opportunities booming so that my folks can come from the villages you know find opportunities etc so I think that is the key point and now it takes me to the Piketty initiative which Piketty's size and many others and going back to the work also of my former colleague at LSE was passed away Tony Atkinson who had fundamental contributions on on on some of these theoretical and income and wealth I think that with liberalization certain opportunities have come up and therefore people have benefited and even poverty has gone down to some degree so this is true right but the question is the disproportionate nature of the gains that have gone to the richest sections right and the fact that for the very lower starter and you know bottom 50% is not the very lower starter that's half the population right and we are not talking about even the extreme poor here their income hasn't grown sufficiently and I feel this is where we need to step out of the kind of left discourse which says everything that happened with liberalization was wrong and we should just kind of focus on redistribution and the right discourse that says okay growth is sufficient right I mean with growth everybody shall be lifted and therefore please don't anything else is somehow left is kind of you know and I genuinely let me interrupt you here essentially these two points of view the left view and the right view is often summarized as you know it's this ongoing debate between Professor Omur Tushin and Professor Jagdish Bhagwati and you yourself have pointed out you know when Professor Simon Kuznetz who got the Nobel Prize in Economics in 1971 he said that when there is a rise in economic growth there's also going to be a sharp rise in inequality quote unquote in the initial stages the quote the point is how how long should those initial stages be should there be for five years 10 years 20 years that is really the issue because what you have also written and what are more than one are many people have pointed out is what we are seeing in India is that the gains of growth it's been distributed extremely unevenly and and it is perhaps manifest most in in in the lack of opportunities for employment for for upward mobility to use your words so this this whole thing this debate between growth versus inequality according to you use you want to take out more what should I say a centrist view and say that you know it is not either or am I correct absolutely right so see the center is always with respect to certain polls and those polls may be a bit outdated so I would like to think of my views at the view that I and I'm not the only one I'm not maybe framing it in this particular way but I would say there's a broad consensus among you know whole range of economies including the kitty size to some of my former colleagues in the University of Chicago economics department which has a reputation of being a fairly free market kind of place which is we need a form of progressive policy which is not necessarily opposed to creation whether it's through private investment you know it doesn't matter whatever creates employment opportunities whatever creates infrastructure growth all that is good right but it has to be a strongly progressive orientation of that policy that in the end if it doesn't do much for the very ordinary member of the population there will be several problems so one problem you could say is the legitimacy problem that eventually the political capital will run out of whatever policies that are you know leading to this right so that's a kind of pragmatic argument of course a more serious argument is the ethical argument you cannot be an economic superpower in the world when you have a bunch a big chunk of your population that is living in very very abject conditions right that's number two and number three and this is a point that I have made in several places and several of my other professional colleagues and friends have made it and others have shown in their work that bringing the poor into the fold of the kind of growth experience right and requires investment in education in health and that will increase supply of skilled labor because otherwise the growth engine will stop eventually in that case growth will peter out right because after while you'll just run out of opportunities and natural resource monopolies and kind of you know really dominating protected markets can only go so far if you're you know you need a you need the dynamism that comes from skilled workers new entrepreneurs and new innovations that come out of this so that's what I so I you know I I'm happy to now clarify any of these points okay so I would say that yes at some point it's a centrist position but I really do believe that there are lots of debates to be had as to how to do this so two points the two questions rather first question is how does India compare with other countries in the world I mean I think the United States is certainly more unequal in both in terms of income and wealth are the other countries who are as per the data that you have as unequal or more unequal I mean how does India compare with countries which are notoriously unequal including South Africa including Russia you have said that India compares very poorly with some of the European countries but how would you place the inequality of income and wealth scenario in India in a global context so let me let me try to try to be brief with respect to you know there's a very very important question and the answer is there are two ways we can look at this so there's a way in which our common friend and Debraj Rai and I did a article a couple of years ago where we were provoked by these Oxfam type reports that every year you know there are this number of billionaires etc which this essay also starts off with right and some may think that's a wonderful thing that India is competing in that league some may think okay with this much poverty that's a terrible thing but question is adjusting for per capita income does India have too many of the super rich that was the question Debraj Rai and I was we're trying to answer in an earlier work that's linked in this particular piece and that answer to that question is yes there is even if you were to say take make India's particularly the same as the US per capita income so you adjust for the fact that you know suppose the US is an advanced version of India in terms of average income then we can compare how many multimillionaires billionaires the US has with India etc and that's where at what we economists technically call the very right tail which is the extreme part of the upper part of the wealth distribution India has more thickness compared to even some of the more rich countries and unequal countries like us so that's sort of one direct way in which one could address the question that India does have its disproportionate share of the super rich adjusting for its overall income levels number two I can if I can sort of sort of summarize what you're saying in simple language you are saying India is relatively more unequal than most other countries in the world can I say that in terms of just that measure even if you adjust for all kinds of things that you know India is not comparable to other countries but even if you do reasonable adjustments yes India has a bit of a bulging upper tail problem and by upper tail we mean in the wealth distribution the very very super rich but what these tables in this article show and you have seen them and I will briefly state what it is but the details are there but this is a very particular measure because you could just say hey that's true but maybe India is otherwise not so unequal maybe for the rest of the distribution of income and wealth maybe India is you know comparable with other countries so this is where the Piketty database that is very helpful and it's publicly accessible tells us is with some exceptions you know the US being an exception South Korea being an exception and there are some exceptions among economies which have huge overall GDP right so you know and that includes France Germany etc India is still quite unequal if we compare the income share of the top 10 percent and the income share of the bottom 50 percent and same holds for wealth so even among this India is not at the very top but even like you said South Africa for example is more unequal absolutely but India still if you look among major economies India does seem to have a more you know greater inequality problem. Okay my last question to you what's the way forward you know we all say that rich needs to be taxed the most but they're not whether in the US whether in India in fact many argue that the rich are getting more and more tax breaks tax sops called the what you like and we also find that the entire taxation system is quite regressive I mean take India when if you look at direct taxes it's about a third of the total tax collections of the government of India whereas two-thirds of the taxes are paid by all sections of the population rich or poor and therefore inherently regressive so it's good to say tax the rich spend it on healthcare spend it on education both are very very solely needed in a country like India but that doesn't seem to be happening one could say it's because of the nexus between big business and politics and the fact is big business is indeed heavily invested and given the way political funding happens this nexus is preventing the taxation or the rich being taxed more than they are being at present. Yeah no I think you're absolutely right that it is not very difficult to point to the general area of the solution okay you can bring the horse to the water that's an entirely different challenge right and we exactly know that for political economy reasons you can advocate capital taxes wealth taxes of various kinds right but is it realistic that that's going to happen very soon even some of the capital gains tax raises that happen have been to some degree you know rolled back you know that that happened a couple of years ago so I really think that other than a kind of sustained sort of demand that the fair distribution of the tax bill has to happen and like you said that you know the fact is India's tax system is not particularly progressive and compared to peer countries or compared to developed countries etc and correspondingly the public service they're living through the pan we are seeing some of the problems that are happening in the public public health domain with the lack of infrastructure and the problems we are facing so see it is very tempting to say something very very catchy and and and kind of magic bullet like and thinking of maybe universal basic income and I have some sympathies for a modified version of it etc but clearly that's not a that's not a magic solution but I would say kind of a consensus around everybody having to pay a fair share of taxes bringing those who are in the informal sector but not poor bringing them under the tax net some of them there should be consensus around these things and I think we can only start with the consensus and putting pressure and in terms of you know having having a demand that these are these need to be done now the only note of optimism if one can master such in the other one is given the whole that this crisis has left in the budget in a way every crisis is also an opportunity right I think there's a US politician some say it's Ram Emmanuel but you know there are others were attributed this quote become a bit of a never waste a crisis exactly that never waste a crisis right so I would say we have a perfect opportunity that given the budgetary crisis that you said that normally direct and indirect taxes are more equal share right but right now they've become disproportionately direct taxes are around one third as you said we really need to have a kind of opportunity to put certain forms of taxation on the table and a consensus from the progressive as well as more pro business ends of the spectrum that you know when some massive crisis happens we have to pick up after it right we have to pick up the pieces kind of emerges that we have to collectively fold the bill and everybody has to chip in and and we have to protect the most vulnerable that is sound fiscal principle in any system it doesn't have to be particularly left in view of the world but that's my hope I wish I could say something more concrete and and that that but that's where we are circling so hopefully there'll be political will for this. Thank you so much Professor Mohit Rish Ghatok for giving us your time giving us your views explaining why despite the recession in the economy stock markets continue to boom why we've seen in the recent past inequalities of income and wealth in this country having widened making India one of the most unequal countries on the planet. Thank you once again for being with us and keep watching NewsClick.


From Soju's radio and television, this is the Army Now. Often called the Peanuts Sorter, the ATACS, or Automated Tactical Ammunition Classification System, is an innovative piece of technology. The idea originated from a machine designed to sort peanuts. The system is capable of sorting everything from 9mm pistol rounds to 50 caliber rifle munitions. The machine inspects each round in 360 degree dimension by type and serviceability, scanning the tip, casing, and headstand for damage and foreign or non-standard ammo. All of the selected rounds are poured into a holding vat that draws them up a conveyor that lines them single file into the image processor, where a computer determines whether it is serviceable or not. Coupled with the Theater Ammunition Reclamation Facility and our D-MIL operations have provided the government a cost avoidance of approximately $20 million over the past 12 months. I'm Private First Class James Bone Jr. from Camp Arifjunk, Wade. That's the Army Now.


He's really been doing it all season long, but what stood out to you about the way Nester was throwing this afternoon? He was the strikeout ball right away. I mean, he was throwing his heater past people. You know, I think his pitch selection was really good. You know, it seemed like they looked cutter sometimes. And he was throwing the fastball. And vice versa, I thought he and Higgy were on a really good page together. And I just thought he was really, you know, really efficient, and stuff was coming out really good. He's finished the season with the best ERA for a Yankee starter since Ron Guidry in 1978. He had a huge ovation when he walked off the mound. Just what do you think that meant to him, and what has he meant to you guys throughout the course of the season? Yeah, I mean, he's been huge.   Who else? Dan and... Is that why you left him out there for the eighth, Nester, to get that ovation? Or was that not it? Might have had something to do with it. But I wanted him to go out and get a hitter out. And with Judge, were you at all surprised, you know, that Baltimore being eliminated now didn't go after him more? I think the one to lead off the, whatever, seventh inning there. Yeah, a little surprised at that one. Otherwise, look, I think it's a hard situation to be in as a pitcher, you know, and it's probably very unique to be in a pitcher where you're striking that balance between I wanna attack him, but it's the best hitter in the world, and my job is to get him out.   I thought that was one where they might go after him a little bit more. It seemed like he kind of ran from it a little bit, but I totally respect that it's a tough situation to be in, you know, as an opponent. Pete. All right now, Cortez's remains so unpredictable against hitters all season. How much of a weapon can that be in postseason? You mean just pitch selection or? Yeah, pitch selection, and even the different looks and angles he gives.  Sometimes I think we focus on that too much and get away from just how really good of a pitcher he is. That's certainly a part of what he does from time to time. I thought today, using some different angles, right from Jump Street, where he dropped down and used both his slider and his fastball, he was really effective when he did kind of go to, you know, where he uses some deception. I thought he was really sharp when he did it today. And it's, you know, it's a weapon for him, but the funky ones that he pulls out every now and then, you know, I think sometimes we run a little bit too much to that being the story, as opposed to a guy with really good stuff that's really on top of his game. Randy. Given that Nestor has been your most consistent starter this year and Garrett has had some struggles lately, is there a conversation possibly that could come whether Nestor could be your game one starter for the playoffs? We'll see when that comes. We're still trying to get through the regular season and got to prepare for what opponent, you know, and hopefully we're going into different rounds and it doesn't always line up, so we'll have those conversations. I think Nestor is three and two thirds innings shy of qualifying for the ERA. It sounds like you're saying that he's not gonna start anymore. If that's the case, how will you keep him sharp? Some live BPs or how would that work?  Ron and Chris, or Susan? Go ahead, Susan. How impressive is what judge is doing with discipline and never really going outside his plan? It's been remarkable. It really has, you know. Yeah, I mean, really it's, you know, I know I've uttered this phrase before, but it's Mike Schmidt used to tell me when I was a kid, take what the game gives you. And Aaron does a great job of that.  So his job is to go up and have a plan and try to execute and control the strike zone, which he's done at such a special level with all this going around him. Ron and Chris? Is there any conscious discussion on the bench to take advantage when they pitch around him, putting him on base, leading off he had a three run first when he got a hit, four runs when he walked in the seventh? I mean, yeah, we were pretty spirited there and, you know, in the seventh when he led off there and we start putting together a rally.  I think guys were feeling and wanting to make sure we cashed those in. And the baseball lifer in you, was there any feeling that it was sort of karma today? 61st anniversary, 61st Homer? No, I wasn't looking at it like that.  Right behind you, Ron. With all the attention that judge has gotten this year, do you feel like in a way Nester season has been overshadowed a little bit? I don't think the legend of Nester Cortez has been overshadowed at all. I think it's, you know, I think he is one of the stars of the All-Star game, one of the focal points of the All-Star game. I think he's as popular a figure, you know, as within this fan base. And I think this fan base certainly appreciates just what he's done for us the last really two seasons now and how good of a pitcher he's been for us. So, no, I don't think so at all. Laura. When Barry Bonds is going after his home run chase, he said that not getting a pitch to hit would sometimes wear him down during the game and over the course of the season. Are you ever concerned that the same could happen to judge, especially going into the playoffs? No, no, and look, the playoffs become a different animal altogether in a different scenario altogether. No, I think he would have worn down a long time ago and so, no, I'm not concerned about that. Meredith and Dan and Bob. Aaron, we've asked you over the past couple of days, if not weeks, about John Carlos Stanton and how he was looking at the plate, absolutely demolished a ball in that first inning. When you see that, what does that tell you as far as the way he's starting to lock in? Definitely good to see. You know, I know he wants to get some traction going here, heading into the postseason. Good to see him get a really good swing off to start off the day.  And then he threw another hit out there. So hopefully these little things that start happening, can start moving him into a direction where, look, we've all seen him against the best in postseason situations. When it's locked in, it's a different level. So keep working, trying to get him there and hopefully today's a moving towards that. Aaron with a historic homerun like, Joe just trying to hit. Would you like to see him hit it here? You know, tomorrow's the last day, would it mean something different if it was here? Well, yeah, I mean, I think there's, excuse me, probably an added, yeah, something to do it in Yankee Stadium and the pinstripes. But that said, if he does it, period, 62 homers is gonna be 62 homers. I mean, that's, it'll be something you see for forever and ever. And I'm worried about the weather now, tomorrow too. So that could be an issue. Last one, Bob.   Given that there will be no homerun record at stake, do you expect teams to go after, go right at Judge Moore in the playoffs than they are right now? Do you think he'll have more opportunities to do damage? Not necessarily, I don't think, you know, no, I don't think people are not going after him to, you know, there's, you can make a case over the last couple of weeks that there's been at bats where there's more of a case to go after him now as opposed to the postseason. You know, I'm sure there's gonna be situations where the other team is probably not gonna want him to beat them. But I don't think all of a sudden the postseason comes and they start just challenging Aaron Judge left and right. You know, I think they're gonna be careful regardless. In postseason, you know, you won't have the crowd booing the pitcher when he goes one and all, you know. Yeah, I mean. I'm sure that's rattled some of the pitchers, Judge's faith. I do think that has some of the pitch, like what I said at the start here, like I think it is a, I'm respectful of the unique nature of it that's gotta be a little weird for a pitcher where you're, you know, in a position where, well, I gotta go after him here, but I gotta get him out to, you know, it's probably a weird predicament to be in for a pitcher right now. Thank you.


In this presentation, we will take a look at overtime calculations. We're first going to look at a time calculation to consider the fraction of hours. Time seems like a fairly straightforward thing to calculate. However, because it's based on 60 minutes in an hour, we have to have that conversion in order to do many types of calculations. In other words, our rates in payroll are usually not in terms of rate per minute. They're typically in terms of rate per hour, and therefore any types of minutes, if we have fractions of hours, we have to convert them from minutes to fractions of hours. So to do that, if we have an employee that worked 45 minutes, for example, if we had the 45 minutes, we divide that by the number of minutes in an hour, 60. The 45 divided by 60 would give us the percent of your time, which would be 75. That would be the percent of an hour. So it's 0.75 of an hour. Now, this, of course, is important because when we have a rate, we don't want to take our hourly rate and multiply it by 45 minutes. That won't work. We have to multiply it by 0.75 hours. Now, if we're considering overtime rates, then typically we think of overtime, the normal overtime rate would be time and a half, time and a half. Now, when we consider time and a half, we have to consider what that means. So if we're saying that we pay someone $10 an hour times time and a half, we could calculate what that is. It's basically a 50% increase in overtime. You can think of you got a 50% raise. So you could calculate that times 0.5, another 50%, and that would be $5 plus the $10. So that would be $15, time and a half. The other way you can think of it, of course, if you have the $10 times 100%, which would be 100% or 1, and then another 50%, which would be 50, so 150%, or 1.5, or time, 1.5, 1.5, 150%, if we move the decimal two places to the right, that gives us our $15. So time and a half, 150% of the original pay rate, that's what we're going to get typically. That's the typical overtime calculation. Other rules can apply to overtime in that the federal law basically means that we can't go over the 40 hours, anything over 40 hours, in other words, would typically be considered overtime if the employee is subject to overtime wages. However, many states also imply or impose a law that says that anything over eight hours in a day needs to be paid overtime wages. And let's just consider that rule eight hours in a day, so that we can see how overtime might be thought of. It's pretty straightforward to look at it in any individual case. But again, if we start to accumulate a lot of data, this starts to get more and more complex. So for example, in Monday, if we had hours worked, 7.5 hours worked in the day, then we're just going to say 7.45 hours is all regular hours, and there's no overtime, because we're not over eight hours. Tuesday, if we're saying that they worked 8.5 hours, which would be eight hours and 30 minutes, if we convert, you know, 0.5 to how many minutes, 30 minutes, we're going to say that that's eight hours of regular pay, and 0.5 hours, 30 minutes of overtime that would have to be paid at the overtime rate. Then if we had Wednesday, we're saying nine hours, that of course would be eight hours of regular pay, and then one hour of overtime. Thursday, we're saying eight hours, all of it's going to be regular pay, no overtime. We got Friday, we worked total of 9.5 hours, according to the time sheet, we're going to say eight hours of it is regular, 9.5 minus 8 would be the 1.5. So that would be the totals here then, the 7.5 plus the 8.5 plus the 9 plus the 8 plus the 9.5 gives us 42.5. We know that the regular pay is the 7.5 plus the 8 plus the 8 plus the 8 plus the 8, 39.5, and then the overtime is the 0.5 plus the 1 plus the 1.5 or three hours. We can calculate that in two ways, we can of course take the 0.5 0.5 plus the 1 plus the 1.5 for the three, or we can take the 42.8 minus the 39.5, meaning this is our total hours, this is our regular hours, these then will be our overtime, or in other words, the regular hours, 39.5 regular hours plus the 3.0 t hours overtime gives us our total hours of 42. Now again, we're applying an eight rule a day type of limit here, anything over eight hours a day would have to be paid time and a half, that's our assumption. If on the other hand, we're just talking about a 40 hour work week, meaning anything over 40 hours would be overtime, then we would just take the 42.5 0.5 minus 40 to get 2.5. So you just got to be aware of what the overtime regulations could be, it could be on a weekly basis, where we would take the total per week, subtract it from the whatever requirement would be, and in this case, 40 to give us the 2.5 overtime, or if we have some type of daily requirement, whatever that daily requirement is, and it can be, note that companies do have a decision if they want to pay overtime as well, so they have to comply with the minimum regulations, which would be federal regulations, and typically the state regulations being some type of higher limit, and then they can apply whatever they want in order to incentivize people to work overtime, and so it could be whatever the overtime law is, so just know the theory of it, and then be able to apply whatever it may be, it might be a weekly rate, which can be nice, because some people would prefer, and you can give options if you are an employer, and you have something like a 40 hour weekly rate, and then anything over that would be overtime, because then you can tell people, well, how about you only work a few, like less days a week, four days a week, at a higher number of hours, more than eight hours a day, and you'd get to that same 40 hours, whereas, so if you work four days a week for like 10 hours a day, then instead of five days a week, you can get a whole another day off, and put four days at 10 hours, many employees might like that better, even if they don't get to pay the overtime, so note that a daily limit, while it could help people to not be working too many hours a day in an individual day, it can have some detriments as well, by basically preventing employees from possibly having options to work different type of pay schedules that they would enjoy working, so there's pros and cons, whatever the payment structure is, note how to put that in place, note that the daily method is a little bit more complex as well, it's not that hard in any individual day of course, but as we start to compile data for long periods of time for an individual employee, and long periods of time for multiple employees, it could start to be more complex. Next we want to look at a standard type of rounding system, note that if we're paying someone hourly, typically they're going to be logging in and out of the system, and the system will just time stamp whatever they log in and out of it, so if we have a digital system or some type of time clock, we can imagine the old time clock will they punch in, or if we have a time clock that's online, then we check in and out, clearly it's not going to be exactly on the hour, so if we, if we for example go in at 9.03 a.m. and punch out at 1.05 p.m., well what do we do with those minutes? Typically we're going to round to like a 15 minute type of estimate, so every 15 minute type of estimate because that'll make it nice and clean for us to do our payroll calculations, so here it basically around 9 to around 1 would be 4 hours, right, 9, 10, 11, 12, 1, and then if we are going back from lunch at 1.30 about 1.29, 1.30, and then we leave at 5.25, then again this is close to, if we round this up to 1.30, and this is going to be close to 5.30, so we are typically going to say that that's going to be 1.30 to 5.30, and therefore 4 hours. Now again different companies might have different types of conventions, and you could argue well that if this is the case people have an incentive to come in, you know, a few, a few minutes late, or leave a few minutes early, but typically if we're talking about a few minutes it's not going to affect behavior too much, and therefore that's typically going to be the rounding type of convention we can use in our time sheets when calculating number, amount of time at the end of the time period in order to calculate our payroll.


Oh We're doing a video Hi, my name is Nicole Fox and I just purchased this vehicle from Mountain View Dodge Love Patsy. Love Chad. Love Wayne. Thank you very much for all of your help and Lots of awesome rides to come Thanks


Now, the other kind of systems what are known as the wide boiling systems, wide boiling systems temperature drops are substantial from top of the column to the bottom of the column. Crude column simulation is a good example of a wide boiling system because you have the lightest material present in the in the form of methane and you will have hydrocarbons as heavy as C 40, C 50, C 55. So, it is a wide boiling system. Now, in wide boiling system these enthalpy is changed significantly because the constituents are changing significantly and therefore, delinking temperature profile may not be a good idea. The same applies to non-ideal systems ethanol water system. There is tremendous interaction of the energy balance with the material balance because the heat of mixing effects or volume change of mixing effects non-ideal effects are significant. So, a method which may work very well for a simple propane propylene column the same numerical technique may fail for wide boiling system or for a non-ideal system. In fact, for non-ideal systems the literature will tell you that the simultaneous approach where all the equations are solved simultaneously is the best way to solve the distillation problem. So, there is a popular algorithm on which there have been lot of variants in last 30, 35 years. The algorithm was published in 1971 in A I C H E journal and it is due to Naphthili and Sandholm. These are the two authors Naphthili and Sandholm. It is popularly known as Naphthili Sandholm. So, what they did? They presented this mesh equations with some modifications in a form that total number of equations were not n times 2 C plus 3 rather it was reduced to n times 2 C plus 1 by simply embedding the summation equations along with the component balances and rather than working with x i's and y i's they defined their unknown variables as component flow rates. So, L multiplied by x becomes the component flow rate. So, they cut down the number of equations by 2 on every stage and then the whole set of equations which is n times 2 C plus 1 is solved by Newton-Raphson technique simultaneously. So, that was a turning point in the theory of distillation. The mesh system could be solved very successfully, but the moment you talk about simultaneous solution let us not forget about one thing that if you have 100 trace in the column and 10 components. So, even for Naphthili Sandholm 10 will give you 21 equations, 10 components will give you 21 equations, 100 trace in the column. So, that will give you 2100 equations. So, you have to solve 2100 non-linear algebraic equations simultaneously in addition to the effort you have spent to calculate the thermodynamic functions. These equations assume the k value is known, the enthalpy is known. So, thermo also has to be put into the system. So, in earlier days when the computer memories were limited simultaneous solution was something very difficult to do. It used to be very time consuming exercise, but today memories are not limited. You configure machines with 2 gigabyte memory and 4 gigabyte memory and therefore, 2300 is nothing, you can even solve 10,000 equations simultaneously. So, simultaneous solution is what we look forward to today, but as I said that the thermodynamics handling could be very tricky. So, therefore, you cannot apply directly the Naphthili Sandholm technique or the Newton-Raphson method and you have to have better numerical techniques developed. So, that the physics of the process is preserved, the iterations do not go into infeasible zone and you are still solving the system simultaneously. So, there is guarantee for convergence or at least the probability of convergence is very large. So, what are the limitations of this equilibrium stage model? In general vapor and liquid streams leaving a stage are not in equilibrium. We know that and we have been saying that equilibrium is there because the residence time is not sufficient for equilibrium to attain.  In actual practice, one problem which is always experienced is that vapor velocities when they are significantly high and columns when they operate at low pressures, the velocities could be fairly large. There is entrainment of liquid, liquid droplets get entrained with vapor and that affects the mass transfer, that affects the efficiency. So, there will not be equilibrium. So, one way is that you bring in the tray efficiencies into picture and handle that part of the operating problem. Now, comes the question that we can bring in efficiency, but how do we define efficiency? Well, there are various ways people have tried defining efficiencies. There is a point efficiency, there is a mercury efficiency, local efficiency, there is a stage efficiency, there is a column efficiency. The fact remains that efficiency is something which is not only tray dependent, it is not only location dependent, it also depends upon the component. On the same tray, if you have nitrogen sitting with benzene and toluene, so benzene versus toluene, there will be a different efficiency. Nitrogen versus benzene, there will be a different efficiency because efficiency is something which is related with the escape tendency. So efficiency, if we represent that as eta, let us say eta ij, it is a function of j anyway, it depends upon the location of the tray because temperatures are different, pressures are different. It is also a function of i, the component. So, if I have a 100 tray column and if I have 10 components, then how many efficiencies do I have? I have 1000 efficiencies. On every tray, I have 10 efficiencies. How do I get all those numbers? It is not possible. So, you go for tray efficiency. You say on the given tray, all components have same efficiency. That also is not true. And within the tray also, we know that the height of the liquid on the wear side is lower than the height of the liquid on the other side of the wall because there is a gradient. And therefore, the efficiencies are different because the bubbles are bubbling through. The time spent is different for different bubbles. You are very right. Mesh equations are not taking into account. And therefore, if I solve mesh system, I am not getting what the industry shows or what the actual column shows. So, there is error. So, there is a mismatch between the simulated results and the actual results. So, one way to now come closer is that I see what is happening in an actual plant. In an actual plant, there is entrainment and there is no theoretical stage concept there. It is an actual tray. So, how do I do that? So, I take the mesh system and I bring in the concept of efficiency. So, question comes that what is the efficiency you would like to use? So, if you look into the simulators, you will find that they have made provision for what is known as a column efficiency, a tray efficiency, mercury efficiency, so on and so forth. It is up to the user to decide which efficiency works best for you. So, there is tremendous amount of uncertainty which is there in the prediction of efficiency. It is a handle given to you to match the performance, but how to use that handle that is not clear. Column efficiency, you are simply saying that every tray let us say if it is 80 percent efficient, then if I have 100 theoretical stages, then actual number of stages is simply 100 divided by 0.8. What I am saying is that every tray cannot be equally efficient because tray below the feed are handling primarily heavier compounds, tray above the feed are handling primarily lighter compounds that is right. Even in rectification zone depends you know if you have close boiling systems, then efficiencies are very good. If you distill propane, propylene using valve trays you may say 85 percent efficiency will be attained, but in benzene toluene column, if benzene toluene we are talking about efficiency will be very good 80 to 110 degrees 30 degrees not too much of a gap, but because benzene columns operate with nitrogen blanketing due to safety reasons due to pressure control requirements. So, nitrogen blanketing is done. So, at the top of the column nitrogen is present with benzene. Now, nitrogen efficiency is very different as compared to benzene and toluene efficiency because nitrogen will be present in distillate in very small amounts. And if it is not acceptable, then what you do is you do not take the top product as your product, you withdraw your product from second or third tray, pasteurization column as it is called. Yes, the efficiencies depend upon the chemical system itself. For the same tray, if I was using that column to separate ethane ethylene and another column same tray propane propylene because the operating conditions are different because the species are different, the efficiency of the trays will be different. So, efficiency depends upon the chemical system, it depends upon the temperature, it depends upon the pressure. And because it depends upon the chemical system, it is location dependent. Top of the column will have different efficiency, bottom of the column will have different efficiency. So, that is what it says that uncertain quantities like efficiency, HETP are used to correct for the departure from composition equilibrium because we have no other way out. This is the only way out, we do it. Component efficiency is very widely on a stage and from stage to stage. I have already explained this to you and there is no unique definition of efficiency. So, this remains a fuzzy area, it is a hazy area, you know it is not very well understood. Efficiency, HETP cannot correctly account for departures from temperature equilibrium. I have already mentioned that inability to account for the interaction effects between simultaneously diffusing species. This is another deficiency, not applicable to chemically reactive systems. Of course, we have not talked about the reactive systems at all here because we have only focused attention on mesh system. Mesh system purely takes physical process, vapor and liquid in equilibrium. We have not gone for reactions. In actual columns, not in all columns, but quite a few columns always there are some reactions occurring. Refinery columns this is a big problem at the temperature at which the column is operating 300 plus degree Celsius, certain amount of cracking occurs inside. Thermal cracking is occurring and that is not there in the mesh model because we have not made any provision for the reaction. Sometimes polymerization reactions occur and of course, this model has no provision for anything to be predicted, everything all data should be known externally. So, there is another approach to modeling and simulation of distillation systems which is known as the rate based approach. So, let me spend a few minutes on rate based approach. Rate based approach is well suited when you have packings as contacting devices because with packings, HETP is a very approximate approach. Mesh system works fairly well with efficiency is incorporated when you have tray columns, but when you have packed columns the HETP approach is very approximate and therefore, you require better modeling tools. So, we go for rate based approach. In this particular approach, we do not assume that there is equilibrium. You take the segment of the packing. We can always make HETP equivalent to a stage and we can say that vapor leaving the stage is in equilibrium with the liquid leaving the stage, but we know that in packing the mass transfer is occurring continuously. Liquid and vapor they are in flow in a continuous manner and therefore, we never will talk about liquid leaving the tray and vapor leaving the tray that kind of term and there is no concept of equilibrium. The only assumption which is made here is everything is governed by heat and mass transfer which means the area, the interfacial area which is available to achieve the heat and mass transfer. And at the interface, at the interface there is instant equilibrium because there are no resistances that is the only assumption which is made. So, this is a depiction of the rate based approach the way it is modeled. So, you have a lump or mass of vapor which is travelling and you have another lump or mass of liquid which is travelling in this direction. There is mass transfer. Now, when I say arrow is on this side, this is just a convention again for the net mass transfer. We know that distillation is a counter current heat and mass transfer operation. It is not unidirectional. You know you are having mass transfer as well as heat transfer in both the directions. But again you have to have a convention. So, this is just a convention that this arrow represents net mass transfer. So, there is mass transfer in this direction also and you have energy transfer. So, this is the interface which is shown like curved line. On this interface we can apply the two film theory of mass transfer. So, this is the interface in here this one magnified and two film theory. So, we are saying that there is a thin vapor film in which most of the resistance on the vapor side resides and a thin liquid film in which most of the resistance on the liquid side resides. So, all the concentration gradients they are contained concentration gradient as well as the thermal gradient the temperature gradient they are contained within the film. Now, temperature as you can see it has a point of continuity whereas, the composition has a point of discontinuity. Why do you think there is discontinuity here? Because that is where y equal to k x is applicable. No, here we have gone from vapor phase to the liquid phase. Now, in this approach again my presentation here is rather qualitative I am not going to write the equations again just to tell you how it is done. The mass and energy transfer rates depend on concentration and temperature driving forces which is expected. Of course, liquid and vapor flows play their role and all sort of fluid properties will now come into picture because the mass transfer and heat transfer coefficients need to be calculated. In equilibrium approach we never asked for any property only equilibrium constant the thermodynamics support is what we were asking. Now, here we are going beyond that thermodynamics alone is not sufficient you need other properties. And of course, the calculations are very much functions of the contacting device what is the kind of contacting device you have. Because the interfacial area, area creation for heat and mass transfer depends upon what contacting device you have. So, we are not talking about a stage now we are talking about a segment a segment of a contacting device or you can call that as a segment of a packing a small section of a packing. And we know that it is no more in equilibrium it is a non-equilibrium. So, concept of a non-equilibrium segment. Non-equilibrium segment refers to a tray or a section of packing of specified height we are just deciding 10 centimeter 20 centimeters. It is just like when you want to integrate a differential equation you take a finite step. If the step is small enough it is good because it takes care of the definition of the differential very well. If it is large then that definition will be violated. When the steps are large number of integrations calculations are less. So, there is inaccuracy in the final result. When the steps are very small the round off and truncation errors may dominate and still you may not get the right results. So, you need to decide what is a good number of steps. Like if you integrate an equation using Euler's method or Nangekata method we have to decide whether 100 steps are to be taken or 1000. If somebody says take 10000 larger the number of steps not necessarily that the answer is right because the round off and truncation errors may dominate. So, similarly here if I take small small segments I will be doing too many calculations and if my variables do not show sufficient change in that segment the numerical errors may dominate and I may get erroneous results. If I take two larger segments then I will be approximating properties in that particular segment and therefore, I will be introducing error otherwise and therefore, we have to have a judicious choice of how many segments. It has been observed that for conventional columns conventional packed columns any number between 20 to 40 sometimes maximum 50 gives you reasonable results. So, that is the meaning of segment we are talking about. A packed column or a tray column can be considered to consist of sequence of such segments now. So, we are making segments and let us see what the treatment is. So, we again go and write M equations. We have to write 6 equations here and these are popularly known as MERSC equations. So, M equations which represent the component material balances. These acronyms have been or abbreviations have been written in such a way so that the end user can easily remember these terms there is nothing special about this you know. So, they represent material balances. E equation unlike in our mesh system where E represented equilibrium E here represents the energy balance on the segment. Our equations represent mass and heat transfer rate equations because it is a rate based approach. So, the mass transfer coefficient and the heat transfer coefficients will come into picture the interfacial area will come into picture the driving forces will come into picture. Then H equations represent the hydraulic equations or the pressure drop. So, momentum balance is built in into the system. In distillation basically it is a discretization approach you are moving from one tray to another tray and we said we can load the profile. In a packed column loading a pressure profile is not that easy if it is linear profile you can load it. You can define at the top you can define at the bottom and you can join it by a straight line, but if it is a non-linear profile how will you load a profile pressure profile in the column? It will be infinite number of points and therefore, it makes sense to embed the momentum balance along with other equations. We did not do that in the mesh system. H equation represent hydraulic equation for pressure drop and Q represent the equilibrium which is only prevailing at the interface. One element is missing here which is the S. S again is the summation equation. So, basically you write all these equations and for the segments you collate all these equations. These equations again will be algebraic non-linear set of equations and you solve these equations to get your final solutions. One very popular software which is available by a separate license unfortunately we do not have it here in IIT is ratefrag. Ratefrag comes as part of Aspen Tech technology. If it has then you can try I think the rate based approach will not work because that comes as a separate ok. So, Merch equations. So, what are the advantages? The advantages are that now that we have integrated or we have taken small segments just like you take differential segments in integration. So, do we require efficiencies? The answer is no. There is no question of efficiency because you are moving with the height of the packing alright. So, we do not require efficiency that is the biggest advantage. So, that is a that is a gain that is a plus point, but then the question will be then how come we do not use it very frequently. Well, we have solved one problem, but we have created another problem. What is the problem we have created? It requires tremendous amount of properties and it requires good correlations for heat and mass transfer and we know that the theory of heat and mass transfer itself uses empirical formulae. So, how good is the mass transfer coefficient? How good is the heat transfer coefficient? Ultimately we will decide how good is the solution through the Merch equations. So, that is the problem we have added, but if you are confident for your system that you have very good mass transfer coefficients, you have very good heat transfer coefficient, the Merch system will work very well. So, uncertain factors such as efficiency, HTTP are avoided, predicts departure from temperature equilibrium which is the actual case in practice. We say vapor liquid equilibrium is there. So, the first condition for vapor liquid equilibrium is the thermal equilibrium. So, vapor leaving the system is in having the same temperature as liquid leaving the system, but if you took actual column and if you put the temperature probes and measured the temperatures, you will find that the vapor temperature is always different from the liquid temperature. Temperatures are never the same. Why? Because there is no thermal equilibrium. Here we are not saying that. So, we are closer to the actual situation. Of course, it predicts accurate composition, temperature and flow profiles. It is a rigorous method. Accounts for interaction between diffusing components. So, we do not worry about efficiencies being different from different constituents because the diffusivities would have taken care of the efficiency part. Influence of reactions are handled correctly. You can put the reactive system if you wish. In my model, I have not shown you the reactions and it is predictive because once you have the correlations for a component for which you did not have data, you can predict the mass transfer coefficients, predict the heat transfer coefficients. Let us now spend few minutes trying to understand that when we were configuring columns either through mesh equation or through mesh equation because those two are approaches to do the model building. When it comes to solution strategy, we have to make sure that the degree of freedom analysis is right. Degree of freedom analysis means that I have number of equations and I have number of unknowns and I will be able to solve that system only if number of unknowns is exactly equal to number of equations which is known as the deterministic system. If I have more number of variables than the number of equations, what kind of system is that? Number of variables are more and number of equations are less. That is called an under defined system. An under defined system is a system in which number of variables are more and number of equations are less. All the configurations which I showed you with mesh equations or with mesh equations, this will fall under the category of under defined system. If I sit down and count the number of equations for mesh, I have already done it for you. I said n times 2 c plus 3, I did not do the count and the number of variables, you will find that number of variables are always more than the number of equations. So, this formulation gives us an under defined system. On the other hand, if there was a system in which number of equations are more and number of variables are less, that will be called as an over defined system. In modeling and simulation, we never encounter when we do mathematical modeling from the basic principles like these models are called transport phenomena based models. So, we are using basic principles. Normally, you get under defined systems. You do not get over defined systems. Over defined systems you get or you come across when you do statistical modeling, regression, data fitting. Here, we will get under defined systems. Now, if I have under defined system, which means there are degrees of freedom. There are some decisions which I have to take before the system becomes deterministic. Only then, I will be able to solve that system. So, that is what it means. What are the common specifications which I need to make? So, there are some guidelines we need to understand. We have written mesh system for a column where the stages were labeled from 1 to n. It implies that the number of stages are given, because we are not calculating number of stages. We are saying number of stages are given. So, n is given. Unlike Fenske-Underwood-Gilliland, we said we can fix the reflux ratio and calculate number of stages. No. Here, in regress model, number of stages are given and we are doing performance evaluation. So, it is a strictly simulation problem. It is not a design problem. I am not designing the column. I have to configure a column. Number of stages are given and now I have to do the performance evaluation of that column. The answer is, the answer should tell me how this column is going to behave. So, number of stages are given. Now, if it is a simulation problem, I had mentioned this to you yesterday that the feeds are to be fully characterized. All the feeds are to be fully characterized. And therefore, for each feed, the flow rate, the composition, the temperature and pressure. So, this is required minimum and this you can satisfy the GIFS phase rule. The GIFS phase rule will tell you how much you need to specify, so that all the calculations can then be done in a deterministic way. When I say all the calculation means if flow rate, composition, temperature and pressure are given, I can calculate the quality of the feed. I can calculate the enthalpy of the feed. I can calculate the total entropy flow. Everything I can calculate. Now, talking about how the feed relates to the structure of the distillation system, I need to define the feed location or the stage entry location. That also is to be given. We are not calculating. I have to say I have 20 stages and feed is on tray number 9 or tray number 11. So, I am spelling out. For each product, for each product, now this includes top product, bottom product and all other products, the stage removal location is to be known. So, if I top the term itself says it is coming from the top. So, I do not have to specify anything more than that. Bottoms means it is coming from the bottom, but the moment I say is liquid side draw, I need to specify from which particular tray I am removing that side draw. If it is a vapour side draw, I need to give the location of the vapour side draw. So, what it means that I must specify the stage removal location. For each intermediate heat exchanger, intermediate means condenser and reboiler not included. Condenser is top, reboiler is bottom. Any other exchanger is intermediate. The stage location has to be specified. Even for pump around, we have to specify the location. If it was a pump around, there also we have to specify the location. Yeah, but then that is not coming back to the column no. See once vapour is taken out, condenser becomes an external piece of equipment. That is no more interacting with. That is right. So, you may be condensing before sending it to storage. So, that condenser is not part of distillation. If you are returning, then that heat transfer is part of distillation calculation. Now, if you did that, it turns out that still the system remains under defined. This anyway we have to do, which I have written on the earlier slide. System still remains under defined. Now, unfortunately, we do not have time. Otherwise, I would have taken you through calculation of the variables and calculation of the equations and we could arrive at a very interesting result. The result is like this that for a given column, given column means number of trays are given, whose feed is specified and I said feed should be specified, whose pressure profile is known, pressure profile is loaded. So, it is known, whose configuration is given. So, let us say if it is a conventional column, conventional column will have one condenser at the top and one reboiler at the bottom. There are no side draws, no side liquid drawl or no side vapor withdrawal. The degree of freedom is 2 for a conventional column or one way to remember is that the degree of freedom is equal to the number of heat exchangers on the column. So, if there is a condenser and there is a reboiler, the degree of freedom is 2. Had it been stripper, what is the degree of freedom? Stripper, steam stripper, steam driven stripper or absorption column, let us say an absorption column. What is the degree of freedom? In both the cases, the degree of freedom is 0. For stripper also it is 0, for absorption column also it is 0. What it means that for absorption column, the vapor coming from bottom is known because that is a feed to the column, the liquid coming from top is known and that is also feed to the column. The number of stages are given, the pressure profile is loaded. So, you have no handle left. The column will have some performance which is deterministic and mesh equation will solve it, mesh system will solve it. But if I replace stripper by a reboiled stripper, then degree of freedom will be 1 because I have added one heat exchanger. So, I need to specify at least one more variable before the system becomes deterministic. So, that is the interpretation of the term degree of freedom. So, what we are saying here one for each product or end heat exchanger. Now, if you have a conventional column, so I am counting the end heat exchangers, so degree of freedom is 2. But suppose somebody said that I am taking a withdrawal from in between. So, there is one more degree of freedom and what is that question? The question is how much are you withdrawing? The flow rate, that could be one question or somebody can say that flow rate is a floating variable you calculate for me, but that particular stream should contain 80 percent benzene. So, that is also is one more specification. The freedom is with you, you can decide what you want to specify, but the degree of freedom analysis has to be satisfied, is this clear? So, one for each intermediate heat exchanger, one for thermal condition of each product and if not saturated, if it is sub cooled that also we have to worry about. Now, what is the interpretation of this? The interpretation of this is that whatever model we have written for mesh system, we have assumed that the liquid which is returned by the condenser at the top is at its bubble point because it was internal reflux. All internal refluxes are at their respective bubble points, but in actual practice the reflux is never at its bubble point because it comes from the discharge of a pump. So, it is a sub cooled liquid, it is 4 or 5 degrees below the bubble point and you do not want bubble point liquid to be taken through the pump due to cavitation problems. So, it is intentionally kept as a sub cooled liquid. So, then the question comes that what is the degree of sub cooling? So, that becomes an additional degree of freedom. Is this clear what I have said? So, one way to count the degree of freedom is make a conventional column with one exchanger at the top, one exchanger at the bottom condenser and reboiler and say the degree of freedom is 2 because those are end exchangers. Then for every heat exchanger in between one additional degree of freedom, for every product withdrawn there is an additional degree of freedom and you have to satisfy that many degrees otherwise you will not be able to solve the system.  So, they will catch you like they will expect you to go on clicking till the degree of freedom is satisfied. So, you do not have to really exercise from your end, the software does it for you. The movement degree of freedom is satisfied, the menu will become gray and it will not allow you to exercise any more option, it will say that too many specifications you are trying to give. I have mentioned something about the wide boiling system and as I said that refinery processes when they deal with distillation of crude etcetera, these are really wide boiling systems. So, refinery processes are relatively more difficult to converge using these mesh systems as compared to close boiling systems. There are some other differences which exist in refining processes due to which you need to carry out more modifications to your mathematical model and one difference which I think I have already mentioned to some extent is that typically water is present in refinery columns because of steam stripping which is carried out and then this water gets condensed in the condenser. So, the reflux drum which is attached to the condenser by and large has a three phase system. In our mesh system we did not make that provision, though I mentioned to you that I can add that additional feature and use the same set of equations. So, a refinery column should have facility for a three phase calculation to decant free water from the reflux drum. Not only that it has pump amounts which you can approximate by stage heat exchangers, but strictly not that also I mentioned and you also have side strippers and we have not looked at side strippers at all. So, actually refinery columns are interlinked distillation columns. You have a main column and then you have tiny tiny side strippers which are again columns because strippers are also columns. So, stripper will have its own mesh system and then that mesh system has to integrate with the mesh system of the main column. And in addition to that the material which you are handling inside the column the crude itself is a continuous boiling system and its characterization needs to be done. It is not a pure component system I cannot say there are 10 components 15 components. I need to characterize that and for characterization there is a procedure unfortunately I do not have time to go through those slides I should have done that it will be there in your notes. So, maybe you can spend some time to go through. So, refinery columns because of these complexities are treated separately though internally the mesh approach is used, but you will find that different modules are there because those modules are catered specially for this application. So, like when we talk about Aspen when we are doing distillation other than refining radfrak will work very well. I am not saying radfrak cannot be used for refinery calculation it can be, but then they have given you an alternate module which is called Petrofrak which is dedicated to refinery columns because of some of the issues which I have mentioned here. And you will find same situation in many other simulators that for refinery applications separate modules are given, but in the background in either case you are solving either the mesh system or the merge system. Let me just show you some of these methods which have been developed for solution of mesh equations and there is a very nice guideline which is available in a book by Kister. The name of the book is distillation design was published in 1992. So the choice of model whether you are using a simultaneous solution using Newton-Raphson that is normally called as global Newton method. There are ways to handle thermodynamics separately from the solution of the distillation equations and a very popular algorithm due to Boston and Russell it is called inside out algorithm which you will find as the default algorithm in most of these simulators. Radfrak uses inside out and then there are many other algorithms which will appear on the next slide. The decision depends upon the chemical system not on the configuration, it depends upon the chemical system. That is why in the beginning if you recall I mentioned that if I have close boiling system the algorithm may work there and it may fail on the wide boiling system. So it is a chemical system which defines which particular algorithm you should be using. So we ask this question that how ideal or how non-ideal is my chemical system. So answer could be that it is highly non-ideal moderately non-ideal. So if it is highly non-ideal I would assume that it something to do with those constituents where the activity coefficients are very large. So ethanol water I will put in this category it is a highly non-ideal system. Is it moderately non-ideal moderately non-ideal means that some non-ideality is there but it is not too large. So may be high pressure system but you are handling with equation of state. So gammas are greater than 1 or less than 1 but it is not very, deviation is not very large. Or idea are close to ideal benzene toluene falls in this category. Surprisingly ethyl benzene styrene system also falls in this category. You can use ideal behavior and you can get beautiful simulations done. Then the next question will be what is the boiling range? And of course as I said we normally divide into two parts here they have clubbed these two together. So narrow boiling or middle boiling and wide boiling. So the methods which work well for narrow boiling may not work that well for middle boiling or wide boiling. Then comes the question about the type of calculation. Here it says distillation here it says distillation and absorber and stripping because absorber and stripping are typically wide boiling systems. When we say I am absorbing acetone from air using water. So when I have air, air has oxygen, nitrogen and at the room temperature conditions they will remain non condensables cannot condense them alright. So basically gas liquid equilibrium comes into picture. So it is basically a wide boiling system. Then I am sorry the question will be about the configuration. So first priority is the question of the type of system and then second is the configuration. So do you have a simple column with few feeds, side draws and heat exchangers or a complex column? I have shown you examples of complex column also. Is the column short or column tall? Short means alphas are very large, tall means alphas are close to one, close boiling. So depending upon this type of characterization then recommendations are there whether you should use inside out algorithm or you should go for some other algorithm and you will find that in every simulator at least three, four different algorithms are made available. There will be a default algorithm but additional three, four algorithms will be there. So if default does not work the user can overwrite that option and choose a different algorithm to solve your mesh equations. The global Newton method which is the most popular method it works very well for all these type of applications distillation, chemical absorption, reactive mass transfer dependent which is your non equilibrium. Again short or tall if it is short column then there is a technique called the relaxation method that is used. If it is tall column then there is a method called homotopy continuation technique that is used. Aspen heises has these methods available if you are working with Aspen heises. In terms of trends today I think the modeling of most conventional columns of any type of configuration has been perfected and simulators very successfully are able to simulate. What is now being done is to expand the scope for simulation of more complicated cases such as azeotropic systems, extractive systems. Not that the present methods cannot do it but the probability of convergence is lower than what you get in conventional columns. So more and more stable numerical methods are being developed to address these questions. So in terms of emerging trends reactive distillation is one area where lot of focus is being given and this is the slide which I had shown you at the beginning yesterday and various aspects which are related with the theory of distillation. This part I have not touched.


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Hi, good morning, and welcome to today's product and focus looking at the US 30 there You can see he's been volatile last couple of sessions and with Friday the 2nd of Jan Having a candle that's indicative of a move higher But then that collapsed later on in the session to bounce off the 21 period SMA Moving on to today's candle on the 5th January. You can see that we're still hovering around about 17 and 7 3 8 And most other global equity markets are actually down this morning US 30s is kind of playing catch up with some of the other markets Over the Christmas periods a couple of bits of US data that came out That was a little bit substandard and that's had a little bit of pressure on to there They were still seeing some interesting moves in the US dollar that I'll come back to in a little second So looking at the UK 100 again incredible amount of volatility that we that we've had here already in today's session You can see there that we briefly ticked above 65 89. I want to get pushed right back down We're almost back into the negative territory today I'm looking at the infidels charts that has been very volatile up one minute down the next up again and down again And now we're trading blow with the 21 and 55 period SMA, which was adds a little bit weakness on to UK 100 Which could be showing a move down to 65 15 should that pressure continue So then looking at Japan 2 to 5 long-legged candles failing to break through 17 Let's just say 17 500 driven below that 21 period SMA and the other technicals are relatively neutral And these last couple candles actually have been I've been pretty ugly now dollar yen is back above 120 But it seems to be more More of an equity sell-off right across the board as most other markets are actually now to begin to talk more about potential quantitative easing especially over in Japan and over in the eurozone as well So moving on to that dollar yen Position as you can see there we've managed to get back above 120. We're now gonna be eyeing up 121 spot 87 We are trading above the 21 period SMA, which should be good in the short term Other technicals are quite neutral apart from the slow stochastic, which is slightly overbought right now The fact that we're not able to break above this short-term potential resistance in about 120 spot 84 That might still be something that's gonna be quite difficult for dolly and to break as of today Everybody who's still be talking about with Texas crude which down at 51 55 so getting quite close to a psychological $50 round number This has not had that much love But what's quite interesting is when we broke below 54 spot 85. I've had a retracement up there on Friday Which then resulted in the bout of seven again, which helped push that back down again So this could be an interesting pivot level 54 85 We do get any rebound back up to there any point in the future So having a look at gold there Gold's not really doing huge amounts still bouncing around 1186 below the moving averages other technicals are quite neutral Almost got a crossover in the MACD ready to break the zero line Depends for that dollar strength is that's going to continue on and we'll be looking at your dollar and cable right now So you can see your dollar completely smashed through 120 Actually went all the way to 118 70 in the back of comments that my or draggy made there At the weekend, which a lot of people have taken For bait them to mean that they're going to do quantitative easing Possibly announcing it as soon as the 22nd of January that sounds pretty close to be fair And the he really does not really want to do this He's been talking about it for a long long period of time And the market has actually run off those rolls back up to 1953 right now, but 120 was broken We've actually got to go a lot further back now to get the next potential Resistance this potential support Let's go here onto the max time interval Just to give you a bit of flavor of where this could go Actually, we're down there already at 118 spots 72 The next one after that is going to be down here So you're probably looking at a potential move to 116 61 I could just show that one just slightly better Let's say 116 40 And that would be a very very low level in your dollar This is already a five and a half year low against usd So they give you a bit of a flavor how things have panned out and you see a cables being just getting absolutely smashed there On Friday a real negative day on Friday and then breaking below potential support once bought 54 24 And today again Hammer formation similar to what you've got on your dollar right now with the longer-term potential support all the way down at one spot 48 13 So that gives you a bit of flavor what's going on. So we do have a German CPI data due today at one And if we fast forward on to Tuesday, we do have a Chinese PMI data You've got your own PMI data UK PMI data and Throughout the whole day it looks to be that Tuesday's PMI day and Factory orders later on that session and if we go into Wednesday You've got European CPI and then you've got the ADP private payrolls and trade balance data Which everybody will look forward to for non farm perils on Friday as ever keep you on the chart for them Make insights part of your layer and join me again tomorrow to find out what happened next


Thank you, Professor Burke, for the introduction. I would first like to thank the generous donors and the Brain Foundation for the honor of receiving this award for our research. I have the privilege of working with Professor Stuart Grieve at the Translational Imaging Lab at the University of Sydney and Dr. Jeffrey Parker at Royal Prince Alfred Department of Radiology. Health research is into a disorder with many names, but the two the most common, they use the pseudotumus rebri and idiopathic intracranial hypertension. It commonly affects young females, but can occur in any one. And its main symptoms are chronic headache and eye disease, which can result in permanent blindness. A definite cause is not truly known, but what we do understand is that there is a high pressure of the fluid that surrounds the brain. This then begins to block the veins. Inserting a stent or a metal cage within these veins to open up and restore some of the normal blood flow can bring down the pressure, can cure the disease, preserving vision, and getting patients off medication permanently. There's been a revolution in this particular area for this condition in the last 15 years, and RPA leads the world in this area. Now, for any patient to receive this treatment, they must first undergo an invasive diagnostic test. And the test, when I tell it to you, sounds fairly brutal, but it's not as bad as it sounds. We insert wires and tubes, which are passed through a small incision in the groin through the large veins of the body all the way up to the top of the brain to record pressures. This must be done to see if their condition will respond to treatment. Our first but modest aim is to develop an MRI scan to replace this invasive test. Our lab has refined a new type of cutting edge MRI technology, which can exact blood flow in four dimensions in any part of the body, something which has not been possible until a few years ago. This will allow us to virtually explore blood flow through the veins like never before. With the clinical experience at RPA Hospital with this disorder and this new MRI scan, I wanted to collaborate with these world-class researchers into developing advances for the benefit of our patients and to expand our understanding of the condition. Our initial experience with a few cases have revealed some interesting observations, which will help us realize these goals. No doubt we are excited, and we will put this money to good use. Thank you.