Let's keep your place there in John chapter 9. So last week we started looking at the story of Jesus in John chapter 9 curing the blind man. This evening we're going to continue with this story in verse number 13 and see what else we can come up with from this story where Jesus does this miraculous miracle with a miraculous miracle. He does this miracle that the Bible says that no one had ever seen anything in the world like this before. So it's a pretty amazing scenario but some certain things happen here and I want to point out this evening, look down to verse number 13 and let's get started this evening. The Bible says they brought to the Pharisees him that a foretold was blind. So this man has been healed. He was blind from birth. We looked at that last week, looked at the reasons that children could possibly be born with disabilities. We looked at that in detail last week. This week we're looking at the aftermath of the miracles. So the Pharisees now bring this man that was known to be blind his entire life. It was a testimony to everyone around him that this was clearly a blind man. He was born blind. Everybody knew it and now he can see. So the Pharisees are trying to interview him. They're trying to figure out what happened. Look at verse 14. It was the Sabbath day when Jesus made the clay and opened his eyes. Jesus is just messing with them at this point. He's just healing people on the Sabbath day just to frustrate the Pharisees. That's what I think anyway. But anyway, we've already talked about that in previous chapters in John. Look at verse 15. Then again the Pharisees also asked him how he had received his sight. He said unto them, he put clay upon my eyes and I washed and do see. So this guy is honest. This guy is just telling the Pharisees exactly what happened. Look at verse 16. Therefore said some of the Pharisees, this man is not of God because he keepeth not the Sabbath day. So now they're putting something in this man's, in front of this man. They're giving him an opinion. They're telling him what to think and they're saying he's not of God. He did this on the Sabbath day. They're obsessed with the Sabbath day. And others said, how can a man that is a sinner do such miracles? And there was division among them. So even amongst the Pharisees there was this dichotomy. The majority of them were like, he's bad. He's not of God. They're just trying to figure out a way to get rid of Jesus. But some of the people that see these things are like, how could this be a bad thing? He literally did this miracle. He cured this man. It's clearly a good thing. Now look at verse number 17. They say to the blind man again, which is ironic because he's not blind anymore, what sayeth thou of him that he hath opened thine eyes? And he said, so now we get the blind man's opinion. The blind man, first of all, just tells him straight up what happened and how it happened. It's like he made clay, he put it on my eyes and he healed me. I see now. But then he says, so they already told him up in verse number 15 or up in verse number 16, sorry, that this man is not of God. They already gave them, gave the blind man or the man that was healed. They already gave him the opinion that he's supposed to have. And look what he says in verse number 17. He says, he said, he is a prophet. Now he doesn't know about the Christ and all this kind of stuff. He just, he just saying, no, he's a good man. He is of God is what the blind man is saying. Look at verse number 18. So he literally kind of disagrees with the Pharisees' assessment right there. He basically says, he is of God. They said he's not of God. He said, no, he is of God is what the blind man here was saying. Look at verse number 18. But the Jews did not believe concerning him that he had been blind and received his sight until they called the parents of him that received his sight.  They call his parents and they're going to interview the parents. Now this interview goes quite different. Look at verse number 19. And they asked them saying, is this your son whom ye say was born blind? How then doth he now see? His parents answered them and said, we know that this is our son and that he was born blind. So they give that part right up front. Now it all goes wrong in verse number 21. They say, but by what now, let me ask you a question. The Pharisees are talking to this man that was healed. They have had the time to hear this story, to find this man, to call this man to them. What are the odds that this man has not talked to his parents? He has clearly talked to his parents and told his parents exactly what happened, exactly what he told the Pharisees. So these parents know what happened. They know who healed their son. They know how he did it by making the clay, by the story that he just, the blind man or the healed man, I should say, just told the Pharisees. But look at verse 20. It says, is this your son who you say was born blind? How then doth he now see? His parents in verse 20, his parents answered them and said, we know that this is our son and that he was born blind. Look at verse 21 now. It all goes south here. But by what means he now seeeth? We know not. Or who hath opened his eyes? We know not. He is of age. Ask him. He shall speak for himself. Now the Bible actually, we don't even have to infer why they did this, because the Bible actually just tells us why they did this. Look at verse 22. These words spake his parents. Why? So they did know the truth. They did know who healed him. They did know how he was healed. These words spake his parents because they feared the Jews. For the Jews had all agreed already that if any man did confess that he was Christ, he should be put out of the synagogue. Therefore said his parents, he is of age. Ask him. So the title of the sermon and the whole subject of the sermon this evening is going to be these five verses in verse number 18 through verse number 23. And the title of the sermon this evening is leverage. Is leverage. Is leverage that will be used. The problem statement here is that these parents were manipulated successfully. These parents were manipulated with this threat of the temple. There was something that was being held over their head that was used against them to get them to do something specific, to get them to say something specific. And guess what? It worked. It worked in this case. They passed off. They literally denied Christ in these few verses. These people were manipulated and they were manipulated successfully because the Jews that they feared, the reason they feared the Jews is because they had leverage over them. So tonight I'm going to give you three points, three steps to not allow yourself to be leveraged in your Christian life just like these parents were leveraged in their Christian life. Turn to Romans. Actually you don't have to turn there. But I'm going to give you three steps tonight because look, this is real. This is going to happen. This is going to happen to you. Definitely. I'm going to explain to you why it's going to happen to you. But I want you to just follow these three steps that I'm going to give you tonight to make it because here's the truth, folks. No one really has leverage over you. No one. But leverage works and leverage works on Christians all the time.  So I'm going to give you three steps tonight on stopping that and recognizing it and stopping it. The first one is this. Recognize authority in your life. Recognize authority in your life. Some people just can't do this. Look, authority is real. Authority is biblical. Romans 13 talks about obeying the higher powers. There's powers in your life. There is supposed to be authority in your life. It's real. It's biblical. It's from God. You say, oh, just God? No. There is earthly authority in your life. Government is an earthly authority that God wants to be over a nation. Look, there's certain things that they're supposed to do and they're not supposed to do. But, I mean, another one is parents. Parents are an authority to their children. They're an authority that God puts in place. God puts the man as the authority over the household. Parents have authority over the children. Pastors, the pastor has authority over the church.  Somebody that's teaching you something has authority over you in that scenario. It wouldn't work out for a kid to go or anyone to go to a class and be taught something and have no respect for the authority of the teacher in whatever the environment is. God puts authorities in place. You need to recognize authorities. Even government laws and, you know, police and all these different things. I mean, they are there. They are authorities. And as long as, you know, the laws and the authority put in place does not violate the higher power, which is God does not violate the Bible, which we're going to talk about tonight. You know, that authority is there and it is biblical is what the Bible says. I mean, work. You have authority. You have a boss. You have people that are over you at your job, your place of employment, men. I mean, turn to Colossians chapter three. Turn to Colossians chapter number three. Employers have authority. They have authority over their employees. Look at Colossians chapter three in verse number twenty-two. The Bible says in Colossians three twenty-two it says, Servants obey in all things your masters according to the flesh. This is talking about secular masters according to the flesh. Somebody that tells you go dig a hole over there. You work for someone and they tell you to do something according to the flesh. It doesn't say according to the Bible, according to the spirit.  You should do it. You should obey those people that have authority over you. Not with eye service. Don't just make it look like, oh, okay, I'll do it. And then when they turn their back, you don't do it. It's saying actually obey those authorities as with men pleasers, but in singleness of heart, fearing God. And whatsoever you do, do it heartily as to the Lord and not unto men. So this is how you work for a bad boss right here. Because really, you're just doing things as the Lord is your boss. You just pretend like, you know, I don't really like my boss and I think that he's mean or whatever. I mean, probably everybody thinks that these days. I don't know.  That's what the Bible is saying. Of course, if it's something that is, you know, against your biblical standards, that's what we're going to be talking about tonight.  Look at verse 24, knowing that of the Lord, he shall receive the reward of the inheritance. For he served the Lord Christ. But he that doeth wrong shall receive for the wrong which he had done and there is no respect of persons. So look, the first point is this, recognize the authority in your life. Like there are people out there that just can't recognize authority. And I've said this before, I'll say it again, it's a life killer. It's a life killer. If there's nobody that can be in authority over you in your life, you will have success at nothing. You will not have success in the workplace. You will definitely not have success in the Christian life.  So that's the first thing, recognize authority. The second one is this, go back to John chapter 9. Go back to John chapter 9, just keep your place there. I should have told you to keep your place there. But you've now recognized the authority in your life.  Look, I have authorities in my life. Everybody has authorities in their life. That's one thing I've learned like in the secular workplace is there's never a point where you're just not going to have any authorities. There is always, even somebody that owns their own business, they have customers. Those customers have authority over them.  Everybody has authority in their life. So you've identified the authorities in your life. You realize, you accept that, you realize it's a God-given structure. Anarchy is not biblical at all. God wants government. Look, I get that the government is not doing anything that God wants them to do, but the structure of a government is biblical. And we will find out how to actually run that structure when Jesus comes back and does it himself. But until then, we just realize, hey, as long as it's not against the Bible, as long as it's not against what God says, as long as it's not against that highest power that we have in our lives, it's there and it's put there for our protection. Look at verse number 22 of John chapter 9. So we recognize the authority. That's step one. Step number two, we're talking about how to avoid being leveraged in your Christian life. Look at verse number 22. It says, these words fake as parents because they feared the Jews. For the Jews had agreed already that if any man did confess that he was Christ, he should be put out of the synagogue. The Jews had power here. They were in authority here. And they knew that people, this is why even Pharisees that were getting saved, Nicodemus went by night. He was scared. Why? For this reason, they had this leverage. The people that were in authority had this leverage of, if you believe Jesus, we're just going to put you out of the club. And it was leverage that worked. Look, these parents feared the Jews because of this leverage. So the second point in avoiding your Christian life being leveraged by this abuse of authority is to identify the potential leverage in your life. Look, I hate to break it to you tonight, but authority figures abuse power.   I mean, it always amazes me when you see these stories of these rich, powerful people, and then they're accused of these terrible things, and then everyone's just shocked. And I'm just like, why are you shocked? You have these men with just all this power, and what do they do? They just abuse it. They abuse it. They use it to do what? They use it to leverage people. They use it to leverage people, and they use it to get what they want. They use it, I mean, people do terrible things by leveraging their power. It happens all the time, and it's going to happen until the world's over. It's going to happen until God ends this. And you just think about all the Hollywood stuff that comes up. Back many, many years ago, 20-some years ago, I used to really like watching talent shows, especially up-close magic, like the guys that would do the slight of hand stuff. I was fascinated by that, because it just took so much talent to do that, and I was just kind of fascinated by that. But you would see people in those situations where they would have little kids going into these talent shows or these singing competitions or whatever, and you'd see these people just so much talent.  I mean, think of all the stories of all the children, the kids that grew up in Hollywood and all this. They're all just, like, abused and just by all these terrible wicked people. All the women that have been abused, even in the last few years that have come out, they've been abused. Why? Why? Because authority figures with power leveraged that power. That's why.  But adults allowed that leverage to work. What did they use? They used the potential of fame to leverage people. They used the potential of money to leverage people. They used the potential of, you know, in the workplace it could be the potential of power or the potential of, you know, money as well, but maybe a potential of career advancement or whatever it is, you know, to what? To leverage people. So you must identify points where you could be leveraged. Turn to 2 Samuel, chapter number 11. When I was studying through this concept, you know what character in the Bible came to mind? A man called Joab in the Bible. Turn to 2 Samuel, chapter number 11. Joab in the Bible is really a fascinating character in the Bible because Joab is not the king. Joab is not the king. He is the king's commander of the army. He's David's commander of David's army. And David's no slouch. David was no slouch. David was a great warrior. Yet Joab, if you read the life of Joab, that is, it sprinkled through the story of David, Joab is always there all the way up until Solomon, you know, finally solves the problem. But Joab, he's not the king yet he goes and he does whatever he wants.  He just kills them. He's like, there's this guy, Abner, and David made peace with him and tried to bring these two kingdoms together that were threatening to split apart. You know, kind of the old house of Saul had this general and this general came and made peace with David. And David's like, hey, Abner's with us now. David Joab didn't agree because he killed his brother, so he just killed him. Just murders him. I mean, straight up just murders him. Joab then later on in the story literally kills David's own son. I mean, yeah, Absalom was, he was no, he was no gem, but David literally said, don't kill Absalom when they went to war to bring, you know, David back into the kingdom and who kills him? Joab. Why? Because he thought he should be killed. I just don't agree with that. Joab didn't, he recognized David's authority when it suited him. He kills a Mesa. Why? I just don't agree that he should be back in the club. Just kills him. He does what he wants to do whenever he wants to do it. You know what? Under David's reign, he got away with everything. He said, why in the world is that? Turn down to second, look at second Samuel chapter 11. David, David at the beginning of his kingdom or towards the beginning, he commits adultery against Uriah with Bathsheba and then on top of that, he can't get Uriah. Uriah is such a good man. He invites him back from the battle and finds out that Bathsheba is with his child and so what does he do? He tries to bring Uriah back and tries to get Uriah to go back down to his house so everyone will think it's Uriah's child. But Uriah won't go. He won't go because he's too good of a man. He's like, I'm not going down to my house and visiting my wife when all my men are out in the field sleeping in the mud. Uriah is such a good man. He's one of the mighty men in the Bible. So David feels like he's just left with no other choice. We just got to kill him.  Look down to 2 Samuel chapter 11. Look at verse number 14. It says, it came to pass in the morning that David wrote a letter to who? To Joab and sent it by the hand of Uriah. That's kind of a sad story right there. Uriah literally delivered his own death sentence and he handed it to the man that was going to kill him and he wrote in the letter saying, set Uriah in the forefront of the hottest battle and retiree from him that he may be smitten and die. He literally tells Joab to put Uriah up in the front of the battle and then to back away and leave him by himself so he's certainly killed. And it came to pass when Joab observed the city that he assigned Uriah. Joab didn't even question it. That he assigned Uriah to a place where he knew that the valiant men were, meaning he knew that this was a hot part of the battle. And when the men of the city went out and fought with Joab, there fell some of the people of the servants of David and Uriah the Hittite died also.  It killed all these other men that went with Uriah. So he killed, David not only murdered Uriah but he murdered all these men in this scheme to cover up his sin and kill this man. But the point is, is that the letter went to Joab. And I believe, the Bible doesn't specifically say this, but I believe that the reason that Joab just operated with freedom around David is because he knew what was in this letter. He knew that he had leverage over David. And David knew that Joab had leverage over him. Look, David got right. David got right but what David should have done is he should have stood up to the people and said exactly what he did here and he would have erased that leverage from Joab. Just take the heat. Just take the heat. Look, he was punished. Nathan came to him and God knew everything. But the point is, he had leverage against him and it cost him through his life. So you need to find out potential points of leverage in your life. You need to find out places where people could pry on you and then you need to do this. You need to do in number three. Once you have identified those points of leverage that could be used against you in your Christian life, you need to mitigate that leverage. You say, what does that, what do you mean? I'm going to give you two ways to mitigate leverage. Turn to 1 Corinthians chapter 7. And I hope you got to kind of follow me on this because I'm hoping this isn't a thought that just only makes sense to me. It's one of those. It's one of those sermons. All right? So look at 1 Corinthians chapter number seven. The first step in mitigating leverage is making sure that you are the most careful for the Lord. When I say careful, I'm using the King James word careful, meaning I care the most for the Lord. The Bible gives us an extreme case of this in 1 Corinthians chapter number seven. And look, I believe there's a reason that this extreme case is used. But the first step in removing leverage against you in your Christian life is making sure that there is nothing that you care more about or nothing that you are more careful about than the Lord, than your Christian life, than your spiritual life. Because the moment there is something that you are more careful about than the Lord, it will be used as leverage against you. Guarantee, and I'll show you, I'll prove that to you tonight. Look at 1 Corinthians chapter seven. Paul gives us an extreme case here. Look at verse number 32. But I would have you without carefulness. What does he mean by that? He means, I don't want, this is what Paul means by that, I don't want you to care about anything but the things of the Lord. That's what he means in that sense. Look at verse, the next part of the verse. He that has unmarried care for the things that belong to the Lord, how he may please the Lord. Now, you have to understand that Paul is coming from a perspective of being not married. But he's speaking, I am sure he is speaking from experience here. And he gives us some truth about marriage here as well. But he's saying he that is unmarried care for the things that belong to the Lord, how he may please the Lord. He's saying somebody that is unmarried, he basically Paul is saying, from my experience, people that are unmarried, they're more focused on the Lord. That's what he's saying. And Paul is saying, I would have you without carefulness.  And from my experience, the people that care the least about worldly things are the single people. The people that are not married. You say, why in the world, what are you talking about? Look at verse 33. But he that has married care for the things that are of the world, what? How he may please his wife.  But he gives both sides of the coin. But he's saying here, he that has married care for what? The things that are of the world, how he may please his wife. So if you want to be a good wife, don't be pleased by the things of the world. That's the answer for the wives right there. Don't be a wife that is pleased and satisfied with worldly things. Because then you're going to create a husband who's just obsessed over worldly things so he can please his wife. That's what Paul is saying. Paul is saying this is what I see. This is what I see out there. There's a difference also between a wife and a virgin, meaning an unmarried woman because you have to understand that not all unmarried women were in fornication as they are today. So he's saying there's also it now he's going to go after the other side of the coin. He says there's a difference also between a wife and a virgin, meaning a wife and an unmarried girl or young lady. The unmarried woman care for the things of the Lord. So he says exactly the same thing just from the perspective of the woman that she may be holy both in body and spirit. But she that has married care for the things of the world, how she may please her husband. So again, don't be a husband that just cares about the things in the world. Because then you will create a wife that only cares about things in the world so she can please her husband. This is great advice. I mean just a side note, this is great advice for married couples here. I mean the Bible here is saying that the wife is going to be care, she's going to just want to please her family, please her husband, worry about her children, just worry about her household and worry about worldly things where the husband could just get carried away with going out, supporting, getting in that daily battle, you know, it's easy to get caught up in it. But the answer is that Paul is giving is he's saying be a husband and be a wife that is satisfied with spiritual things. Be a husband that is like no matter what happens, we're going to church. No matter what happens, our spiritual life, no one can take that from us. No matter what happens as a wife just be like no matter what happens, my children are going to learn the Bible today.  No matter what happens with my husband's job, no matter if it's a year when we have more money, it's a year we have less money, maybe he lost his job, whatever it is, just care about the spiritual things. But Paul is saying that's generally not what I see. But it's great marital advice. So that's the answer for the marriage. But the point is this, the overall point bringing it back to leverage and the first point in mitigating leverage is make sure that the battle doesn't become the prize. Make sure that, see, because you have to go out and you have to support your family. You have to go out and you have to just like man, I can't support my family, I got to get better at some things, I got to, I got to grow, I got to get some skills, I got to do some things. But as soon as the career becomes the prize, then leverage enters in. And get this, as soon as even the family, Paul says, the wife or the husband takes the place of the Lord, even that will be used as leverage against you. Remember, folks, from Sunday night, there's somebody else in this fight. There's somebody else influencing these situations. There's somebody else that's working against you.  And that's when it will. See, it's the blessings. It's the blessings, it's the good times, it's the good job, it's the good things, is when the potential for trouble comes in. When those things get so good, when those things get so, you get so focused on those things, that is when trouble can enter in. You need to keep everything in its place. You need to keep the Lord on the pedestal. Now let me show you an interesting Bible contradiction that kind of demonstrates the mechanics of how leverage is used against you. Here's a common Bible contradiction that people often bring up. Turn to 1 Chronicles chapter 21. Just stick with me for just a minute here. People will point these two verses out and they will say, see, the Bible contradicts itself, but it just shows you that they have no understanding of how God works and how Satan works. Look at 1 Chronicles chapter 21. Look at verse number one. 1 Chronicles chapter 21, verse number one. The Bible says, And Satan stood up against Israel and provoked David to number Israel. Now turn, keep your place there, because I want you to look at both verses and turn to 2 Samuel chapter 24. So everyone will say that these two verses differ slightly, and they're like, oh, they must have translated the Bible wrong. Look at 2 Samuel chapter 24. And look at verse number one. Of course, a parallel, it's the same time talking about the same event, talking about David going out and taking a census. And yes, God does not want that to happen. Look at 2 Samuel chapter 24. Look at verse number one. The Bible says, And the anger of the Lord was kindled against Israel, and he moved David against them to say, go number Israel and Judah. So again, up in 1 Chronicles 21, in verse number one, it says, And Satan stood up against Israel and provoked David to number Israel. See, in 1 Chronicles chapter 21, verse number one, Satan knew this was wrong for David to do this. And you can see it in the statement. But in 2 Samuel 24, verse one, it says that God took action. And everyone's like, See, the Bible contradicts itself. No, read 2 Samuel chapter 24 one more time. It doesn't say the exact same thing as 1 Chronicles chapter 21. It says, And the anger of the Lord was kindled against Israel. Who was God mad at? Was God mad at David? Possibly, but he was mad at the entire nation. He was mad at the nation. And how did he punish them?   You're like, Oh, man, sorry.  Satan was just a tool. It's just like 1 Corinthians five in verse number five, where it says, where it's talking about somebody being put out of the church, where it says to deliver such and one to Satan for the destruction of the flesh. Satan is just a tool. Satan is literally a tool that God uses at times because all God has to do is remove his protection. And Satan just has a one track mind to just destroy. And as soon as God removes his protection, it's just in the case of something you see what I'm trying to say is in the case of something having power over your Christian life, Satan wants it to have that power. So he can happily let it destroy you. And God, on the other hand, wants it exposed and brought out where you may even if it means a hard lesson for you.  Satan is predictable if nothing else, because all he wants to do is destroy. As soon as he has unleashed, he will just destroy. That's why like Satan worshipers are so foolish. Like these people are like, Oh, I'm a devil worship or whatever. And they get to walk around wearing the devil symbols and you know, all that.  That's what those people are. Because all he wants to do it's not like Satan is this person that's like, Oh, if you follow me, I'll be nice to you.  So he wants to destroy all of man.  But it's just a foolish thing on its face. Satan hates everybody. Satan hates all of God's creation. He's trying to do he's trying to burn the whole house down. So in the case of leverage, God wants that thing off the pedestal. And Satan wants to use that thing to destroy you. The interest could seem the same. But God wants you to get right, you know, so that's why somebody is delivered unto Satan for the destruction of the flesh. He's leaving the protection of God. And hopefully, when he goes out and Satan starts destroying him, he will get right and get back. That's what God wants. So the first thing is recognize that leverage, mitigate that leverage in your life. And look, you got to make sure that things do not take the place of God. Because as soon as they do, this is the first point. As soon as they do, that leverage will be used because Satan as soon as he finds something that he can use to leverage against you, he will use it. He will use it. Here's the second one. Turn to 2nd Corinthians chapter six. Here's the second way to mitigate leverage in your life. Look at 2nd Corinthians chapter six, look at verse number 14. I'm going to apply this verse. We've read this verse many times before, but I'm going to apply it a little bit different here. But it still fits. Look at 2nd Corinthians 6 14. The Bible says, be not unequally yoked together with unbelievers. For what fellowship hath righteousness with unrighteousness? And what communion hath light with darkness? Look, this is a unique application of this verse. But look, it is not wise as a Christian to allow a secular organization or secular people to have complete control over you as a Christian. You know what that would be called? That would be called being unequally yoked.  This is why the Bible speaks that debt could do this to you.  Debt can drive you into that. Debt can cause you to be leveraged. I mean, that's one of the statements of being in too much debt is you're overleveraged. If people have leverage, they can use against you. And that could be more important to you. Look, it should still not be more important to you than your Christian life, but it is something that can definitely be used as leverage against you. Just think of secular authority. Secular authority is real. I just read that to you in Colossians chapter three, but secular authority should never have complete control over your Christian life. It just shouldn't. You shouldn't, you know, how do I mitigate that pastor? Well, you know, one thing that I saw, one thing that I saw in the last couple of years is I saw a bunch of people where their secular authorities in their life was trying to leverage them talking about vaccine mandates and things like this at work. And I saw people that felt like if I lose this job, there is no other way I can find any other job that will pay me anywhere near the money that I make at this job. That is not a good position to be in. You should never stop turn to Proverbs chapter 22. You should never stop developing yourself. You should never stop learning. You should never stop building skills in your life. You should never get too comfortable in whatever area you are. You should be continuously growing and growing and growing. You should be diligent about your business, as the Bible would say. And in verse number 29 of Proverbs 22, it says, CS thou a man diligent in his business, he shall stand before kings. You know what that means? People are going to seek him out. I knew some people, and I actually said this during the vaccine mandates. I'm like, this is, this is crazy. We're going to have a bunch of people out there in the workforce who are great leaders, who are great at their jobs, who are thinking people, who are, you know, they understand risk management.   Because normally those types of people are not looking for jobs yet they were forced out into the workplace. I was like, wow, there's going to be a lot of companies that benefit here. And I saw that happen. I saw at my previous job, I saw one of the best leaders that I worked with. I saw him go to another job because of something like that. And I'm just like, we just lost our, you know, we just lost one of our best guys on this project. But I knew what would happen. Because he was smart, he was a thinking person. All the logical thinking leaders are going to be available in the workplace. I'm like, this can be a great thing for a lot of companies, probably not people that lose them. But the point is the bio, you should just never, you should never, if you are in a position where you feel like, you know, look, if you're in a position where there's only one person, the person that currently pays you that would pay you that kind of money, you know, you're overpaid. Like, sooner or later, they're going to figure it out.  People are going to be after you. And you know what that does? That makes you not unequally yoked with people. That takes away people's leverage.  That's where you want to be. When the kings are seeking you out, you don't have to worry about that type of thing. Never stop learning. Never stop growing. Push yourself. Be someone sought out by kings. I saw this. I saw this happen in the last couple of years. Here's the fourth one, or here's the last point on how to not be leveraged in your life. Once you've identified the leverage in your life, once you've identified the authorities, you've identified the potential leverage and you've done whatever you can to mitigate that leverage, don't compromise.  Because look, this is what we're talking about. You know, that's the example that I use that the vaccine and all that. Look, if people didn't get, if people got the vaccine, I could care less. It's a standard. It's a standard. I could care less. You know what, what bothered me was, what bothered me was people telling me what I had to do. That's what bothered me. But it's a standard. If people didn't have that standard, fine. But set your standards in your Christian life and then pour concrete on them. I had a conversation with one guy at work with all that crazy stuff was going on and, you know, a lot of people were worried and they're just like worried like, oh man, what are we going to do and all this, you know, and I'm just like, I don't know, like, what are we going to do? Like, you're either going to do it or you're not going to do it. And then just like whatever. He's like, he's like under no circumstances. Would you do it?  I'm still not doing it. Pour concrete on your standards. If it's a standard for you, I don't care what it is. If it's a standard for you, pour concrete on it. That's it. It's easy. Life becomes really easy as a Christian when you look at it that way. We just look at it from the, I mean, from all the perspective of the mandates and all this stuff. I mean, standards are standards and like I said, I don't have anything against the people that didn't have that standard. I had people, you know, people telling me what my standard should be, I got a problem there. If it's a standard, see, look, if it's a standard, folks, it'll bother your conscience. If it's a standard, you'll know that somebody is pushing your standards. If it starts to bother your conscience, if it starts to bother the spirit within you. That's how you'll know that it's a standard that you have. Turn to Psalm 75.  There's just things that I do do. There's places I go and there's places I don't go. And they don't change for people. They don't change for what year it is. They don't change for circumstances. That, that's just it. And look at Psalm 75 and verse number seven. You know what that does? That takes away leverage. That takes away leverage that people have over you. Because really, folks, when it comes down to it, look at Psalm 75 and verse number seven, God is the judge. He put it down one and set up, set it up another. Really, any leverage that you allow to have on your life, it's because you are allowing it. Nobody in the United States, here's a bold blanket statement for you, nobody in the United States was forced to get a vaccine. Nobody. Nobody had that gun held to their head and say get the vaccine. And look, and if it wasn't their standard and they got the vaccine, whatever. But if it was somebody's standard and they were leveraged into it, that's not a good thing. That is not, you know, what the Bible says. You need to hold your standards for the Lord. Set your standards and then hold them for the Lord. Because at the end of the day, he's the only one that matters. He sets up and he put it down.  You don't think God can figure that out for you. It's a lack of faith. It's like, no, I mean, I do what I do and that's it. You know, what are we going to do if this happens next week? The same thing we did this week. What are you talking about?  What are we going to do next Sunday? I don't know, go to church like we always do. That's what we're going to do. And what, make sure, another comment on standards, make sure your standards are biblically based.   Write them down. We go here. We don't go there. We do this. We don't do that.  And now, like I said, just cast them in stone. These parents in this story are a great example of what not to do. They literally allowed leverage from evil people to get them to deny Jesus Christ. Identify the authorities. Identify the potential leverage that those people could use. Mitigate where you can. The unbeliever's power over you is it's only in your mind.  What power still do you have over me? Oh no, now I'm in heaven.  Yet people will allow it to control their Christian life to stop their Christian life. Set your standards, pour concrete on them. Hey, let God sort it out. You know, ultimately, if it's if it's your time, it's your time. Let's bow our heads and have a


I'm here from Lawrence Systems and RAID is not a backup, but RAID does offer resiliency from things like hard-dry failures.  So there's data and redundancy across these and you should be good. But what if all the drives fail or the entire system fails? Well, this is where Synology offers a high availability solution. And it's really easy to set up. So I wanted to walk through a tutorial here. So I had a couple of DS3617 XS models that are identical, which is a prerequisite for doing the SoundGHA. They have a lot of different models, even some of their smaller ones that support this. It's not only a high-end feature, but it's a really cool feature to load the high availability application, synchronize the two servers, and then have all of your data, not just in one SoundGHA server, but in two of them. And it is important that these servers are identical. There are some notes in SoundGHA. There's ways to make it work if they're not, but it's not recommended. So if you are planning this out, you get two identical Synology servers, and it's the best way to start out. But I want to walk through how that works, how to configure it, what it looks like, and then unplug it. Just show how you take a server, fail it over and see what happens and show you how it recovers and how fast it can recover, even when you're using it as a storage target for something like virtualization. Before we dive into the details of this tutorial, if you want to learn more about me and my company, head over to LawrenceSystems.com. If you like to hire a shared project, there's a hires button right at the top. If you want to support this channel in other ways, there's affiliate links down below to get you deals and discounts and products and services we talk about on this channel. All right, let's start out here talking about how our lab is currently set up. We have one labeled alpha at 3.52, one labeled beta at 3.53. And then we have a switch. Now, each of these are connected to this switch at 10 gig and the XC PNG hypervisors also connected at 10 gig. There's an add on card in each of these units. They're absolutely identical, including the add in card, the Synology SFP two port connector. This is all connected with SFP cables keeps it all really clean and simple. Now the connection is only using one of the ports on here and one of the ports on here to connect to the switch. And what we're going to do to build our HA cluster is connect this and this directly together with a debt cable. Nothing in between. We don't need a switch for the heartbeat. This is an important aspect of the way that these clusters work to get the cluster working. We're going to load the Synology HA cluster tool. We'll walk through the wizard and then we'll assign a cluster IP address. These will keep their current IP addresses of 3.52 and 3.53 and 3d.54 will become our management address. What the management address and also the shared address between is the one that the active server is handling and whichever server is active, that's the one that handles it. And when you're setting up things like your hypervisor or any of your access to these particular servers, you'll always use that IP address. These will still have these IP addresses on here, but having the management address is so you know exactly that that address is the one that's always going to be whatever server is active. So they actually kind of pass that IP address back and forth. And that's what we'll do in the demo when we unplug the system. Now the heartbeat is actually two purposes. The DAC cable that's connecting in the extra port on the SFP card is facilitating the heartbeat so these two servers know where what they're doing it each time and synchronization. So when data comes in from any of the external servers over the line and connects to whichever server is active, and let's say that the alpha one is active, the data flows in and goes across the line. You don't want the data also flowing back across that line to synchronize all the changes going on to this secondary passive server. So the heartbeat has to be the same connection if not faster than the incoming connection for where the data is. If not, you'll end up with well an asymmetrical connection where the data comes in potentially faster than it can go out and it would not be able to stay in sync with each other to perform proper failover. So they do have to all be at the same speed when they are for this case, they're all at 10 gig. And there's not really a switch needed or really even recommended to go between the devices. Putting a DAC SFP cable directly between these devices is the easiest simplest way. You don't need other things, you know, interfering with it. You could run it through a switch theoretically, but I recommend doing it this way. And it's in the Synology documentation as well. Now let's go on to how to actually set it up. It's pretty easy. Now the first and obvious thing is probably understanding that you need Synology High Availability application installed. Pretty easy to install it. We're going to hit open it up. And now it's going to create a High Availability cluster. It wants to confirm that we have a cluster connection on the switch just like we did in our diagram and the heartbeat connection between them. Create High Availability cluster. Yep. Notice we need a couple of cables. We need to choose the cluster interface. And for that, we're going to go over here and look at the network interfaces. And there's a 3.52 on LAN 5. So the LAN 5 is that. If you notice, there's nothing on LAN 6 that says DHCP, but it can't find a DHCP server because it's actively plugged into the other system. It doesn't need any other settings because Synology can take care of that for us. So we're going to go over here and say that's the heartbeat interface. That's the direct connection, no switch plugged into the other Synology. We're going to go next. Now it sees the other system and we're going to put the username and password in for the other system so we can go in there. We don't have to actually log into the other system directly. We're logged in just to the first system. Next, now we're going to give it a name. We'll call it the Turbo Cluster because that's what my staff was calling it when we were doing the demo here. 683.54. This is just like the IP address that we had set over here, 3.54. So that's what we're going to use. Next, now it's going to verify all the requirements. Make sure that they're the same, make sure the network setup is right, make sure the heartbeat interface is talking. Then we click next and done. I understand all the data on the passive server will be permanently removed and cannot be recovered. I've already got something set up on the active server and it's going to start the synchronization process. It would take a little while because I've got an active ice cozy and storage and things like that is all configured on here. So this is going to take a minute while it verifies all the environment, gets all it's set up and then synchronizes the two. So they're in sync. This will take a little while. So we're going to use the magic of video editing to skip ahead. The high availability cluster is healthy. So the alpha one is at 3.52. The beta one is still at 3.53, but we're accessing everything at 3.54. Now, pretty simple. Once this is set up, if you need to switch something like which one's active or which one needs to be switched over, we can actually just hit switch over and say, yes, and it'll switch them over. It'll do so in a very graceful way. But before we go there, let's talk about the storage setup. Currently, as I said, I have the Synology set up with ice cozy. I have a ice cozy target. It's connected right now to a XC PNG server. And it says Synology HA right here. And of course, when we look at the host information, our target is going to be 54, because 54 is that IP address that is getting passed between the two servers, whichever one has that IP address is going to be the active server. So we connect this here. And actually, I got a Windows server up and running on it. So here's my Windows server 2019. And maybe that's something you want to keep up and running and not have to restart when the storage server has a failure. And this is where the HA comes in of note and not covered in this particular tutorial is I know I don't have redundant switches in this. Obviously, another layer would be to put redundant switches between here. Just of note, this does not protect from a switch failure. So FYI, I'm aware probably already comment because I didn't say it earlier in the video back to the video. The disc here being on the Synology iSCSI and of course, it's up and running. So we'll show you what happens when we do the switchover. We're going to close that and we'll do a graceful switchover. So we say switchover, we say yes, we get a warning that we know that things are connected like iSCSI. We're just going to throw caution to the wind here.  All right, the other server now took over and it's now the active one. And what about our Windows? Is it break? Is it throwing hard drives errors in the event log or anything like that? Actually, no, it's perfectly fine. We can still launch things on it and open up and it doesn't really notice that something happened and it switched over to the other server. This is actually really handy. There's ways you can handle updates to the Synology system this way and, you know, everything will keep working perfectly fine. You can gracefully switch between them. You're doing it in a very controlled fashion. But of course, failures never happen in a controlled fashion. So before we get into the failure mode, let's talk about other services besides just iSCSI, such as maybe running Docker. So we're going to go over here and pull up the Docker and any application really that you load on here. And we have one container up and running up for one minute. And that's because we just switched over. It was actually running for a while on the other server. Anything that you have set up and configured on the Synology automatically replicates to the passive Synology. So the active one has all the settings in there. So because this was in the running state, it will restart. It actually doesn't do any type of live migration between these. The applications restart on the other server, but still all the data is in synchronization the whole time. So other than having restarted, the integrity of the application is there and the services are still up and running. So people may have been logged out if that ran something that would lose sessions upon restart, for example. But at least it's all there. All the other services such as active backup for business and other applications I have installed on here, they would all just be taking over on the other side with no problem at all. I have a couple of different random things that I have set up in here, but they're all just Passover. This does work for SMB as well, the high availability. So if you are using this for your standard SMB rights, maybe a window share with a bunch of users on there and the main server fails and goes over. Once again, they're none the wiser to it because windows will be only connecting to that 3.54 server. But now let's do that catastrophic failure and show you what happens. We're going to go ahead and just rip the plug out of the DS3617 and see what happens. We have our two Synology servers, the alpha beta and it's currently on beta. So we're just going to go ahead and rip that plug out and reach back here. Now, as I said, there's the SFP cards in here. So they're now not talking to each other anymore. It's directly connected. Well, can't really pan out easy enough to get that whole thing in there. But trust me, only one of these goes switch, the other one goes there and it's realized its friend is missing. So we're going to plug it back in as it takes a little bit to boot and we'll see what happens. All right, now let's go see on the screen the failover because it's starting back up. It'll take a few minutes. So we're getting the warning that unable to detect the passive server, it realizes it failed. So it just flipped over. Not a problem. This server is now active and it's telling us actually this passive server because it was active. So it just flips it around. But of course, the important question is, what happened over here? Did Windows die? Did Windows still work? Can we still look through folders and launch things? And yeah, works perfectly fine. No problem at all doing the switchover. The data is synchronized. Now, what's going to happen though? This is where things get a little bit interesting. When this server comes back online, they are going to have to re-sync because right now active data is going back and forth between here. Next, let's go back and open up our Docker image again. Ooh, that container didn't start up automatically on there. So fail on the container to start, but oh, future time here who edits these videos and checks for accuracy. And I realize I did not have the auto start enabled for this particular one. So it actually was supposed to auto start on failure on the other server. It didn't. I did forget to check the box. Just wanted to have this for accuracy in there. That when you do a failover, if you don't have auto start on a hard fail, it won't auto start. Simple as that. Wanted to get this clarification in there. Now I can just hit start and the container is running again. The more important thing for particularly this demo is that one, the data integrity is there so I can still boot things up. And I didn't lose my storage target on my virtualization server because, while keeping this server up and running, you know, might be kind of critical to things. Now, once it detects this, and we'll go ahead and fast forward a little bit, and it does to show you the synchronization, because obviously this has got new data that's been added to it from us reading and writing and windows. Matter of fact, here, oh, it happened pretty quick. So currently we have, we're at 99% it realizes the difference between them. So there's only 1% of data change. The longer you have it off, the longer it would take to change. Also, while the passive server is off, you still can do things such as add other applications, install things from the package center, it'll still let you do everything. And that's just that much more data it has to sync once these things are on there. So even while it's not in sync, it's loading up the package center and letting me go ahead and make changes. Go back over to like all packages. And let's say we wanted to open up something like install Synology office, install. And even though they're not in sync, it's pausing because it's letting it's doing so much synchronization in a background, but I can still say yes and finish this and it'll be one more thing that gets synchronized to here. It'll take a little while and you'll watch right here the transfer speeds between the heartbeat connection. Because as I said, it isn't just the heartbeat to the servers can determine that they're both working, but also so you can transfer that data back and forth and get them synchronized back up. Now until these two systems are completely in sync, it would be dangerous to fail over again because there's data missing on the passive server until it gets synchronized. Just kind of an FYI in there. So you don't want to try and pass them back and forth, but didn't take long. I did that real time there. So you can see your sync. Now a few other options here they have is where you can eject or shut down or restart each of these individually. Like I said for updates, this is where you'll change the network settings in case you want to change things, change some of the host information. These are services like the services you like to enable auto failover when the active server is unavailable. Now this is that auto failover as in make sure these absolutely run when there's a catastrophic failure. And so I SCSI, SMB, I don't have FTP checked. Hopefully you're not using that. NFS shares and web services. Then we have the storage where you can look at it here. And of course logs of what's going on, what happened. And you can actually facilitate this through the Synology Logging Server. So you can keep track of all of it. So hopefully you found this helpful and how to set up Synology HA. And like I said earlier, there's quite a few models that support this. I think it's a really cool feature they've added in, because well, there's not a lot of times HA is that easy to set up with devices, especially when you want to use them as virtualization storage targets. But they've kind of made it as simple as just buy a couple of Synologies that support it and run through a few settings, connect a switch to them. Obviously, if you really want to do this, well connect redundant switches where you take cards where one port goes to one switch, one port goes to the air switch, switch talk to each other so everything can talk and you build that level of redundancy. I'll leave links in a white paper where they explain that a little bit more in depth. If you really want to build this out to more enterprise level, Synology's got work instructions on it, but hey, the settings are the same. You just go through that wizard, like I said, and thanks to you know, you have an HA system. All right, I'll leave links to the things I talked about down below and thank you. And thank you for making it all the way to the end of this video. If you've enjoyed the content, please give us a thumbs up. If you would like to see more content from this channel, hit the subscribe button and the bell icon. If you'd like to hire a short project, head over to laurancesystems.com and click the hires button right at the top. 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I think we will start now. This is the diagram I have also given in the last class. We have seen in mixed flow reactor how easily one can find out the relationship between temperature and conversion, okay. There is no trial and error involved. There is no trial and error involved. Why there is no trial and error involved in mixed flow reactor? What happened to third variable? Because of the space, you know, it is a lumped parameter system, right? Because of it is a lumping parameter system, that is why that changes in the space is they have disappeared. So that is why it became only two parameter problem, two variables, that is temperature and conversion. So normally you know conversion, you can calculate temperature. From the temperature and conversion, you can calculate volume of the reactor. But there is some other problem there when you just observed the equations what we have written earlier for, for q g and q r. What are the equations we have written for q g? Tell me minus delta h r, not that, final expression, minus delta h r, C A naught, V, yeah, whole thing divided by 1 plus, I think in terms of E power and all that we have written. E power E by RT by K naught plus, that is the equation, right? Volume must be there, volume is here, right, right. So volumetric flow rate has come into V, so tau, so that will not be there. That equation I do not have, that is why I am asking you, because I have slightly complicated equation. This is the simple equation. Okay, this is capital V, right? Of course, here again you have volume by volumetric flow rate, so both are there. So now, this is the one q g, q g, what was the equation number? 14, 14, 14, 14, okay. So heat removal line was, this is same what we have, yeah, F A naught, C P or otherwise, yeah, you tell me what is the equation I have given there? That also I have slightly different. Heat removal line, ah, summation of F I C P I plus U A, that is bracket there, into T, temperature minus, ah, yeah, sigma F I C P I T naught plus U A T C, so this is the equation, bracket, right, yeah, so this is equation 15. So under operation these two q g must be equal to q r, because for steady state, right, we are talking about only steady state mixture flow reactor. So this is what we have plotted. We separately plotted equation 14, here this is q g and you have q r lines because this is a straight line, this is y equal to m x plus type, this is y, this is m, all this is x, okay.  Now let us look at these points, like where you have these three for this and one here and one here. Let us start with this is lowest one, where we have, yeah, at this point. At this point if I just look at, right and by chance let us say this is operating at 20 degree centigrade, it is operating at low temperatures because temperature is increasing in this. Let us say we have 20 degree centigrade and let us say because of the flow fluctuation because, you know, you could have seen either volumetric flow rate when you are measuring, if you are using, okay, what are the instruments you use for measuring flow rates? Rotometer. Rotometer. Rotometer. Venturometer. Venturometer. Surface. Surface meter. Yeah, what do you measure in venturometer and rotometer? Pressure. Pressure. Pressure. I do not know whether you looked at those pressures, you know, the manometer particularly when you are using, always that will be fluctuating a little bit, okay, slightly like this, like this, yeah. If that fluctuation causes may be one degree in this direction positive, that means 20 it is operating but it is going to 21. Our question is when you have the 21, that means there is a disturbance from the temperature, okay. This is the point what you get if I solve those two equations, okay, under this conditions, right. So under these conditions if I carefully look at that if there is one degree temperature this way, then the temperature is increasing, right. So naturally what should happen to rate of reaction? It should increase. When rate of reaction is increasing what should happen to heat release? It is exothermic, yeah. Also it is exothermic, okay. So temperature should increase. So once by the by if you do not have exothermic you will never get this shape, right, yeah. And once the temperature is increasing then is the temperature goes on increasing or will it subside? Again come back to this. Why it comes back? Temperature is increasing that means q g line is increasing, okay. Point in the q g line is increasing. So you have at 20 degrees, 21 degrees, temperature increase, rate of reaction increases, heat release increases and it will try to go on this line. But what is happening? This heat removal, the moment it crosses a little bit what is heat removal? Is it is less than q g or less than q r? Or greater than q g? Yeah. So then what should happen now when it is heat removal is more than heat generated? It should come down to because there is only one state. So at that point, so you should come back to that particular point e. Similarly even here it is falling a little bit the temperature by some reason because if volumetric flow rate is suddenly increased also it may fall, right? That means more heat is now taken by the convection, yeah. No, T C also suddenly increases, it may fall. So but even then heat removal line will be, yeah, here heat generation will be less and heat removal is, you know, at this point when you come back heat removal will be less and heat generation will be more.  So then again it starts heating and then goes only to this point. So whether I move in this line, direction or here it is small, in this direction the stable point is only this one, right? So when it is reducing, like for example when the temperature is falling, falling down, okay, the temperature should, the rate of reaction must be less. So heat generation must be less, okay. So then, but when I move this way here, you see this point I have less than, this q g is less, q g at this point below, okay, q g is less. So when q g, sorry, this is q r, q r is less. When q r is less then what should happen again? Okay, it came to 19, right, but heat removal is less. So then what should happen? Temperature should increase. So that means again it will move to this direction, yeah. So that is why even if there are slight disturbances around this point, absolutely no problem, okay. Now let us do, let us talk about this particular case. I think here you can easily see that, yeah, same argument here, so when I am moving, let us say it is 100 degree centigrade and it move to 105, okay, more change. So when 105 it is going, then the rate of reaction should increase, right, heat release must increase, temperature must increase, so it will definitely move on this direction. But now, if I draw a line here, then heat removal is more than heat generated. So what will happen again? It will come back to this state. Similarly here, it move till this point, 95, right, heat generated is more, heat removal is less. So temperature should increase. So again it will move to this point. So that is why even this point also will be steady. It may be fluctuating around this but it will be only on that point. I do not know whether you have discussed this in your process control, okay, huh? Yeah, mathematical methods may be, yeah, you would have, for steady states. This is one of the very good examples for, you know, in chemical engineering steady states, okay, the reactor steady states and, okay, so now this we understood it is steady state and this we understood it is steady state. Now when I have this kind of situation, so we have three points here. Now just try to find out what is happening at C. See also same argument because when the temperature is moving this way, okay, yeah, slightly when it is, temperature is moving this way, so heat generation will be more but heat removal is more than heat generated, much more than heat generated. So again it will come back. That means there is no difference between A and C. Similarly you can also discuss here, when I am moving here, okay, when I draw this one slightly further, yeah, when I am moving this side heat removal is more and heat generated is more, even though there is a change in temperature and the temperature is trying to increase and heat generation will increase and, you know, the temperature anyway try to go on this way Q G will increase but at this point again Q R is greater than Q G. So that means again it has to come back. Same thing here again, when it comes back here then heat removal is less and heat generated is more, so it will move on this line and then stabilize there. So A C E B or A B and C E there is no problem when the reactor is operating at those temperatures, okay. Now without knowing you are at this point. Now the argument must be very easy, right. So let us say this is around 75 degree centigrade. It went to 76, this way, right, this way. So now the moment it went this way, so that means I am somewhere here, okay, I am somewhere here. So then what is the heat generated line this one? What is heat removed this one? So now what should happen to the temperature? It will again increase more, that means more rate of reaction, more heat release, more temperature increase. So you will go here because always here Q R is less, Q G is more, till it reaches this particular point. Similarly here it is same thing, the moment you move this side heat removal is more, heat generated is less. So more and more heat is removed, heat generated is not that much because you know this is the point and this is the point, this is the point and this is the point. So that means it becomes more and more cooling, temperature will fall again but there is a next steady state that is here, let us see, right. So that is why this particular point D is called unstable point or metastable point. So D is metastable or, okay, A, B, C, E stable point and D is unstable. In fact the first chapter of, you know there is a book process control by Stephanopoulos, yeah, to justify why chemical engineers must read process control, he gives this example, okay. Why should we read process control, right? So in the normal way when, even if you do not have control here, no problem for me. Why? Because if there is a disturbance it goes away but again comes back because of the conditions here. So why do I need a control? I do not need a control, right? So but here definitely I need a control, right? So why I need a control? Let us say my, the reaction temperature what I calculated was 75 and 75 is this one but I do not know because of this 14, 15 non-linearity you will get, when I solve this I will get this three points here that means three solutions you get for that mathematically speaking. So that is what is shown here whereas under these conditions that depends on what kind of slope you have, what kind of flow rates you have, what kind of CA naught and you know, yeah, what else, yeah, delta H R all these things will come into picture. So that is why theoretically speaking I can draw Q G by varying all those variables like for example tau changing, Q G alone, forget about the other one we will come back because just as a mathematical exercise how many parameters I have there, temperature is anyway, I am plotting here, Q G is here, the other parameter K naught is constant, E is constant and for a given system delta H R also is a constant then it will change with volumetric flow rate, right? Of course normally the stability and all that will come once you have the reactor, right? But even when you are designing a new reactor the procedure is this, you have calculated using the method what we have discussed in the last class, what was the method, write the energy balance, write the energy balance and energy balance is very simple because there is no trial and error involved for mixed flow reactor. So then calculate temperature for given conversion, take this temperature and conversion to design equation, okay. Design equation is V by F naught equal to X A by minus r A, minus r A has this T and X, right? So then calculate V. So now you know, you also know the, for that particular temperature what is T, that is the first step what you have done, right? From energy balance, T you have calculated for a given X. Now the question comes whether that temperature is stable or not, that is why this analysis is required, right? So how we have to do is, people who really like mathematics they simply go for these equations and try to find out by trial and error, okay or using some method to find out whether there is only one solution or more number of solutions, okay and this is, okay, I also have to write it is simple reversible, sorry, irreversible exothermic reaction, okay for this case. Again the moment I go to irreversible, sorry this is the irreversible, reversible and also if I go to A going to R, R going to S, right? So exothermic, all the cases will be different, good. So now the criteria given for necessary condition, okay by the by, I think you know this point A will happen point A and point A no one would like to operate, why? Conversion is very very small, okay corresponding to this, because temperature is very very small, right? So conversion also will be very very small. So that is the reason why normally we do not want to operate but here we would like to operate. So for that reason sometimes you have to move the T not, correct no T not values. So that is why by taking this equation T not is here, for different T nots and for fixing you know normally we do not change T C, once you fix T C and once you fix the heat exchanger this is constant, right and for a given flow rate and all that this is constant only T you can vary and then draw various lines, all will be parallel, why parallel? Because slope is not changing but T not depending on that, that is also important for us because all this is happening because of T not also, right? So I may have, if I fix T not like this one line, another line like this, another line like this, okay this also possible, another line like that, all that I have to do. So now when I am doing all this, the slope is falling, correct no, yeah and also yeah the operating temperature will be increasing because when I put here and then draw this line, I am talking about if I fix this, right and also it is definitely better to avoid this point because if I fix this point I have to draw a line like this otherwise it will touch here, correct no, it should not touch here, right, this line, Q G line, the moment it touches then you have a solution there. So to avoid that you draw the number of lines with T zero as parameter and then you will have an idea of where you have to fix that temperature, T not, okay, good, fine. So now, yeah the conditions for A, conditions for A are 1, low K value, K means reaction rate constant or 2, it can be low tau, low tau and it also can be small delta H R and also it can be small V into C A not, V into C A not is nothing but F A not, okay. So it also can happen with low T C, okay or it can also happen large, large U, large U A or separately U or A also, correct no, all these are common sense now once you understand that, why? Because low K will give me low conversion, low tau also will give me, okay, why? Why low T gives you low conversion?   So in between, yeah, unfortunately sometimes you have to fix only this condition because even though this gives me more conversion, if I draw a line here, temperature may be let us say 175 and that 175 will spoil my product, okay, so that means there may be side reactions or that may be, it may be charred because it depends on again you know what kind of products you are dealing with, so the physical properties of the reactants and products, so that will also once, yeah, ignition point, you know, there is a flash point where it may catch fire beyond certain point, so all this will happen here and I do not know whether you have observed this, how many of you used Bunsen burner, only used burner, not for cooking or doing experiments I am dealing with, yeah, Bunsen burner, only 3, yeah, what raised me you have never used Bunsen burner, used it, but the question is so stupid, so that is why you do not want to say anything, yeah, because you have used but did you observe something peculiar there, can you stabilize the way, when do you stabilize the way, low flow rate is this, you cannot, because there must be a balance between the amount of, you know, the gas coming and also the temperature that is able to sustain, there must be a balance. If you also use too much gas, you know, that also not sustainable, if you use too less gas then that is also not sustainable, okay, that means you are somewhere here, right, but if you correctly use the amount of gas and also, you know, there must be oxygen supply also, that is why you have, in the bottom there are 2 holes, 2 or 3 holes I think, okay, yeah, did you observe, you know, Bunsen at the bottom, that is only for oxygen to enter, so that sucking if it is not that much, then it cannot stabilize, so that means there is, there must be a balance between amount of oxygen, amount of fuel and then it will sustain for long time, otherwise you send too much oxygen, too low fuel, it won't, twice versa, too much oxygen but very, I am sorry, too much fuel and less oxygen again it won't sustain, right, and how many of you, it is a bad question, smoke, none of you, all good boys and girls are, okay, good, yeah, now a days girls also happy smoking, you have seen TV's and all that, and I think in Hyderabad there are many pubs it seems where you go and ask why are you smoking means what is wrong if I smoke, nothing is wrong, nothing will happen, only your lung will disappear after some time, that is all, I think, okay, yeah, anyway, any smoke of any kind for lung is very bad, lung does not like smoke, it only likes oxygen, okay, good, anyway, so when you are using matchstick, matchstick, right, when you hit like this, particularly rainy season and all that, will it catch fire, okay, when it is not catching fire you are under what condition here on this line, the lowest condition, that means here practically you don't have any reaction, okay, and then you may again strike and then wait for some time without even shaking and all that, then it catches fire, and also that phosphorus which is at the tip of this matchstick, it will also make some peculiar sounds like that, okay, so when you have that sound can take you either to this point or this point, right, I think, you know, you don't know, this is an experiment what you can do, you may not get in your house, okay, so you can buy a matchstick and then go on experimenting on this, whether it is really, you know, this point, right, sometimes when you strike you will get spark, but it will not catch fire, that means temporarily you are at this point and nowadays, I think not nowadays, in this season all of you are going to destroy your environment because of diwali, correct, no, diwali, you burn lot of crackers, I feel, I think practically you are burning money, that's all, nothing else, I think it is waste, as chemical engineers no one should do that, why? Pollution, bain karam pollution, I think in fact I think you should not, yeah, and you also find out, you know, the moment you, if you are standing there, you know, so many people may get wheezing and all that, right, so there also, you know, normally we have that, yeah, that crackers, red ones and Lakshmi is very, very Lakshmi cracker is very, very sound, lot of sound it gives and there are other things also, they tie with something and then also, what do you call that, that is called atom bomb, atom bomb without atoms there, okay, okay, so that one also will give you, so then what we do, we will put that here and then go to, like this, you take that very big stick, you know, with that fire right there and then slowly put, but I think, yeah, I mean you are afraid that suddenly it may blow up, so that is why you just touch and then come, touch and then come, so that is why it may, stop, stop, stop, I like that it may go, because that fuse is there outside, right, till, that means there must be a sustainable fire in the fuse itself, then the fuse goes and then opens up, okay and why you should give lot of sound, yeah, what is, what is the simple formula they use there in making crackers, there is a equation, beautiful equation that is involved here, huh, yeah, what, I am just asking only equation, no explanation, yeah, what equation? E equal to mc, yeah, he said only E equal to mc square, you are telling E equal to mc square plus xA plus xB plus xC, yeah, see how sad it is, you know, that means we are studying in the, this is high school question, okay, simply it is P v equal to R T, that is all, P v equal to R T, nothing else and we, I think till now 25 years we have burnt so many crackers without knowing what is the formula behind that, okay, anyway at the age of 2, 3, 4, 5 you may not know, but once you go to school you should know that equation P v equal to R T, why it is P v equal to R T, volume is kept constant, okay, that is not moving, yeah and temperature is increased, right, so P v equal to R T, volume constant, R is constant, temperature is increased because of explosion, then what will happen to pressure, pressure should increase, but you are having that, you know, papers or some kind of threads and all that around that, but you know if you have too much threading and where it is not at all able to crack that, then you do not get any sound, really you do not get any sound, so that means that pressure it is able to contain, like you know ammonia reactor, ammonia reactor thickness of the reactor is, I think you know it is 4 inches, 5 inches still, right, so it will not explode, if it explodes that is I think 1,000 times Lakshmi cracker, okay because 500 atmospheres, correct, 350 atmospheres or 250 atmospheres, okay, it will be very high, so that is the reason why that P v equal to R T, that is why in Lakshmi cracker you will have slightly tougher more number of papers, that smallest one is the red one, okay, so that would not give that much sound, so some people I think people like merit and all that they will have hold it in hand and then crack, not afraid at all, he is bold guy, so that is the reason why you know no problem at all, there are some more things you know that red small things, caps are something they call, that red very small one I think maybe 5 mm, 6 mm diameter and inside you have small thing and you take one stone and then heat it, okay, so I am training, I am giving training, I am giving training for you for Devali, okay, what are the fundas, so you put that and then take a stone and then heat it as if you know it is a great thing and no one will hear except you, so sound is so small because explosion is so small but still it gives sound because of the pressure you know which you are creating, what is Swami, cracking something there, cracking jokes on it, gun, gun, gun, gun, gun, yeah yeah, but gun is also mechanical, it is not purely chemical, gun is mechanical right, yeah, when bullet is leaving, what is that, that is okay, yeah, it is not the right question also because as you are applying the i thought he is talking about okay good so all these things are happening so that is why you are getting more and more sound now someone ask why let me use more sound than some other small one small one is called what not the round one that same cylinder type and then small one cracker only so Benzels don't know sound see all our diwali thing see either sound or light you will have pencils and you will have sudarshan chakras so all kinds of but poor fellows they do not make nice they will only make light so that is what i think you know even this particular curve is also responsible for that m-i-c disaster no m-i-c disaster in Bhopal civil engineers can be really dangerous they can kill many people civil engineer if he kills i think only building falls so all of us how many 60 people may not be there in the world if it falls or may be some more people down so now it deans room and all that just below this only deans room is there but if gas leaks and then you cannot stop bridge wherever it goes it kills you know what has happened there at that time there was that m-i-c stored and it is a catalytic reaction it seems in the presence of water the reaction is much faster water by mistake or so water entered so reaction started and it is highly exothermic reaction so the moment water small amount water has gone and reaction started then temperature is increased so that temperature again heat released exothermic reaction temperature increased that temperature increased again rate of reaction so that rate of reaction again created more temperature it goes on building it because there was lot of m-i-c stored but unfortunately if that kind of things happen they should have a safety wall that safety wall did not open but it is a concrete tank but the pressure inside is so much like this crackers okay if that tank is very very strong it could have not happened you know if that concrete tank if it is very very strong it could have not happened that is why if you go to this nuclear power plants that thickness of the walls where 3 meters, 4 meters, 5 meters depending on the amount of fuel you put there thick okay and that much is required because I think those everyday activity should not diffuse again through concrete I think that is why civil engineers also study diffusion of concrete through porous media like you know this concrete and those people who are doing this construction or that structural engineering concrete and all that they also study that diffusion because that should not come out right so all these things are just because of this you know exothermic reaction and temperature going on increasing so that is why endothermic people are very happy that is why most of us I think you know if there is an active fellow only problem if inactive fellow there is no problem okay he is anyway inactive he may not even laugh also because he may not have even patience to laugh that kind of endothermic reaction so that is why I think anyway this is also very good so all these things may happen that is why we are getting this particular state either go here and then go here and when I told you that when this unstable state is trying to go here then if this is explosion point if this point is explosion point then the entire reactor will explode okay so good so this is fine so then mathematically speaking the condition here why it is stable or here or here okay or here why it is stable that is given is as a q slope of du d t must be greater than this is the slope criteria this is sufficient condition no sorry necessary condition necessary condition for stability okay so that means if you take these two equations and then you can differentiate okay you can differentiate this and once you differentiate if you know all these values you will be knowing definitely you can also differentiate with respect to t and delta h are all these values you can substitute and then calculate which slope is more right so depending on that value you can find out whether the system is stable or not but that gives you only one condition that is necessary condition but the sufficient condition will be the sufficient condition is doing in terms of process control what do they do for process control they write unsteady state equations because i told you know all process control people are unsteady state they do not have any business in steady state okay only unsteady state so once you have that unsteady state equations and then you have to expand those terms you know the tile spirit and take like the way you do and take the first few terms and then write the equation you get one condition where change in temperature delta t will be some constant into m 1 t plus b into this you should have got many times i am not doing all that m 2 t when you say that the condition will be you know stable the point will be stable when m 1 and m 2 must be real values are negative right so that is the condition so now you have to do this and you have to also write the material and energy balances and then write the equation you know in terms of the tile is expansion and all that and then bring it to this level and then try to examine what is m 1 value what is m 2 value if you do that this m 1 and m 2 contains all these parameters this m 1 m 2 contains all these parameters like you know delta h r all these things will be there tau v okay all these parameters will be there so then m 1 and m 2 are negative real parts or negative real parts if then system is stable this is very good condition because you have to do this this is one condition necessary condition this is sufficient condition both one has to check whether it is really yeah stable or not okay good excellent i think this is nice this is very nice interesting thing but i tell you give the same thing in the examination you will have help because you do not even know how to plot and if you are going by trial and error okay thinking that okay you know i like mathematics and then i will do it but in the examination call you cannot do because it is exponential you have to find out three values and you do not know first of all there are three values there may be two sometimes depending on the shape of the curve right so that is why by trial and error if you do do not blame me because you may take three hours for one problem okay yeah for one problem you may take three hours by trial and error but if you draw the graph correctly you may get quickly you may get provided you also know how to calculate correctly q g q g is the main problem q r is not that problem because straight line fellow all curves are dangerous only straight lines very happy no problem at all right so that is what as far as examination is concerned so this is what is the condition in fact there is lot of information available on this you know you should have heard of limit cycles okay and also unsteady state you know when process control people analyze this system they start this is unsteady state at time t equal to 0 they start and till what time it comes to this stable point if that is the point that is there so if this is the point wherever you start so there are lines like this goes goes goes finally goes to this point and you may start this side this side means low temperatures high temperatures different flow rates all that okay so that phase diagrams are beautifully given wherever you start how this comes to finally to your stable point and there are also you know things called limit cycles I have not gone through all that because I think my interest is just to expose you to this and then move to residence time distribution because we are losing time now right yeah so that is why I just want to point out all these things to you those who are more interested because that goes into process control I mean I told you if you would have started with definitions already known very well that means 1st 2nd 3rd 4th 5th chapters of Lounspale is completed I should have started with 6th or 7th chapter then we should have done all this I also should have enjoyed that but I think now it is more fundage and also exposure to as much as possible okay that real things that are necessary so that is the reason why I am not able to go to that kind of analysis in terms of unsteady state otherwise it is not only the business of process control people even though I am telling many times but it is also a reactor design engineer duty to find out whether the system is stable or not and if you use this only one condition that may not be sufficient okay so that may be necessary but I think that condition again may not guarantee stability okay yeah so that is the reason why what is that yeah I mean see when you are starting this in the beginning itself no problem but as a chemical engineer I mean sorry as a reactor engineer what do I do I design this steady state reactor and then I go for unsteady state okay to check whether only for in this case right so that is the reason why I am telling this one first because my idea is first to calculate what is steady state temperature now go to the analysis so at that time if I say that yes I have one more point yes this is necessary I mean necessary condition this is stable right and this is problem for me because I mean I can do the second step this one to find out whether guaranteed stability or not okay good and for endothermic reaction this kind of things will not happen why endothermic reaction this kind of thing will not come into picture at all mathematically also you can tell what will be the value of dqg by dt for endothermic system can you say zero negative okay and what will be the slope dqg by dt is nothing but slope no will it be any time negative extend the brain a little bit I say expand the brain why ua cannot be negative and fi cpi cannot be negative I think you know that kind of expansion must be there in the brain I say only simply nodding hands and I mean heads and all that I think you know that expansion when does that come fire okay immediately before the teacher tells that you should have told the answer at this point of time you know it is very easy I told you know can it be negative and you have the straight there and that is why the physics unfortunately unfortunately is missing whenever in all the subjects and you are interested only in of course in examinations that is all may have you may be thinking that whether this fellow gives problem in the examination or not if it is not in the examination I will switch off the brain if it is as if there is lot of things in the brain so switching off because I think too much loading and all that is a problem right I think this can take you know this is only we have now 1 terabyte GB right as the hard disk only 1 terabyte increased more than 1 terabyte also available but this one has infinite terabyte but if you have willingness to accept willingness to learn then only it has terabyte unlimited terabyte but if you are restricting to only examinations all the time that will be only 256 MB that is why it will never grow more than that 256 is half of that also came in the beginning I think only 256 I saw the minimum one 64 umbers also was there so that is all so that is why I think may be at PHD and MS MTech may be that goes to 256 a little bit more so that is why don't imagine all these examinations and all that okay good so this is the one what we have about this one and so that is why endothermic reaction is not a problem another question I ask is why I have not talked anything about plug flow but why I am talking about only mixed flow is it possible to have multiple study states even in plug flow no expansion only 256 maybe 64 mb or 32 mb or 16 mb so what will happen why not so what happens okay it is varying continuously heat removal is not there heat removal is there you put outside jacket anybody interested in control here or all may be interested in control those who are taking I think PHD why the fact that we have not discussed that you know there must not be any problem I am asking why what area is yours real logical so you are not only reality she always flows rest me control yeah rest me control I saw only PHD control or something but now this has been rest me control shall I give one word it depends on the feedback now I can tell rest me measure temperature I mean any number of thermocouples I can put beautifully I can measure because here whatever temperature fluctuations are there that is going as feedback to the reactor and then slowly it is increasing but what will happen in a continuous flow along the length of the reactor if there is a temperature fluctuation what will happen to that temperature fluctuation you told like this so I thought you understood just wash it out so in it that means there is no feedback so there is no point for the accumulation of the heat there but here the heat that is which is about to go out will be brought back and then mix with the feed that is why it is called back mixing reactor so that is why this happens inside and temperature multiple study states is not a problem with normal plug flow but we have another problem there what is called parametric sensitivity in terms of plug flow and also batch reactor batch reactor also same problem in time forward it moves okay but I think that is what Ramakrishna has done I think none of you solved that problem did you solve the batch reactor problem which I gave you no no not simple adiabatic batch non-isothermal adiabatic batch nena reactor batch reactor none of you solved I am not asking about quiz I am talking about batch reactor which I gave you in the class for adiabatic system but did you do this by trial and error no no UA that is what I am telling adiabatic only you solved some of you but you do not even know that there is a problem for non adiabatic which I gave you I think it is 0 mbis so not even 64 absolutely no storage space there so then he has done it and he found that at one point the temperature will shoot up all the time you know normally what we expect when you have non-isothermal it has to go to maximum and then fall but that will not happen in mixed flow in batch reactor and mixed flow because you will get that point only under one UA condition UA heat removal because that is the parameter I have given you to change right but I also gave you in fact how much is 2 4 or something like that yeah 111 UA so then only you could get increasing and decreasing that will be stable points I mean not stable so that will be maximum and then fall but here a small change in UA will be shooting up you know that is called parametric sensitivity that means by chance there is a small temperature change okay along the line of parametric sensitivity it goes up and shoots up okay so I am not able to do that because again you know my time in other portions I have to do that I just want to mention first of all in plug flow reactor you will not get multiple steady states under normal conditions as you are going to r and all that okay yeah so then I think again I do not know about what happens in autocatalytic in plug flow okay yeah so but this one for normal reactions plug flow will not have multiple steady states but you have another problem called parametric sensitivity that is the problem what you will have there so that means there will be uncontrollable parameters after some conditions okay at some conditions that also one has to find out okay that is only the problem there and very beautiful information is available by Amundsen you know Amundsen is another grandfather of ours mathematical methods in chemical engineering there are books you know three books by Aries and Amundsen okay so I think Amundsen was the actually this multiple steady states first found out by Fan Hadin I think I do not know I will just put that Fan Hadin he is from Netherlands Netherlands is also a beautiful place for for chemical engineering in fact chemical reaction engineering name came from Netherlands I told you know you would have forgotten again 0 MB okay in the first few classes I told that and who was the person also I gave name the person who told chemical reaction engineering how beautifully he coined that name okay yeah I think I have to stop here but I think still I am not able to complete this also so I have to tell one more one or two things about this like for example adiabatic case what will happen UA is 0 this UA will be 0 then you will have only these two so then this must be equal to that equation equal to QR adiabatic case this is 0 this is 0 must be equal to this multiple steady states why no yes why yes because the line will still be there not only line will be there but QG will be there as usual QG a shaped curve will be anyway will be there okay so that is why only this slope will be different now because UA term is not there that intercept also TC and all that is not there intercept will be there but is only this term only this term T0 okay FICPA T0 so that is why even for adiabatic case also you will get multiple steady states okay good I think we will stop here because you have to go to class now