So remember that Ptolemy's Alamages began with a table of chords in a circle. Now, given chords, subtending central angle theta and rho, Ptolemy also included theorems for computing the chords subtending the central angle theta minus rho, the chord of the difference, and the chords subtending the central angle one half theta, the chord of half the angle. However, we can go more simply using only the Pythagorean theorem Indian mathematicians could find the chord of one half theta, which relied on the half chord. The half chord became even more important with Islamic geometers who considered problems involving sundials. As the sun moves, the shadow of the nomen can be used to determine the time. Now the actual path of the sun across the sky is very nearly a circle. And so the line connecting the tip of the nomen to the sun's position traces out a cone. That comes from Apollonius' reinvention of the conic sections. And the plane of the ground cuts the cone. And so the tip of the shadow traces out a conic section. And one consequence of this is Islamic geometers became very interested in conic sections and developed a number of important results about them and using them. We'll take a look at some of those results elsewhere. Now, while we're used to thinking of sundials as objects on the ground with a vertical nomen, this isn't always practical. Only those nearby can actually see the sundial. And the sun will actually be blocked by buildings. So more practically, the nomen might be stuck on a wall and run horizontally. And so more people can see it. And if it's high enough, it won't be blocked by other buildings. Now, since the length of the nomen is fixed, this gives us two more lengths of interest. First, what we could call the length of the shadow of the horizontal nomen or the length of the reverse shadow of the vertical nomen. And similarly, if the nomen is perpendicular to a surface, it forms a right triangle. And this gives us two more quantities of interest. The hypotenuse of the shadow and the hypotenuse of the reverse shadow. In the 10th century, Nasser Adin described these lengths in relation to a circle. Suppose we have a horizontal nomen OA on vertical wall AE. Since the nomen has a fixed length, we can make OA the radius of the circle. Suppose the sun's angle of elevation is theta. The satellite cuts the circle at some point B, and GB will be the half-court of theta. AD will be the shadow, and OD will be the hypotenuse of the shadow. On the other hand, if we have a vertical nomen OC on ground plane CF, then HB is the half-court of the complementary angle, CF is the reverse shadow, and OF is the hypotenuse of the reverse shadow. And this gives us six values for any angle theta. The half-court, the half-court of the complement, the shadow, the reverse shadow, the hypotenuse of the shadow, and the hypotenuse of the reverse shadow. Since the length of the cord depends on the radius of the circle, we'll use capital SINE theta to refer to the length of the cord GB, where the radius is implied. Islamic Geometers recognize that, given the sine and shadow, the remaining lengths could be determined from the Pythagorean theorem, so they focus their efforts on finding these values. For example, suppose we want to find the sine and shadow of 30 degrees, and we'll assume a radius of 60, which Islamic Geometers usually did following the tradition of Ptolemy. And again, once we have the sine and shadow, we can also find the sine of the complementary angle, the reverse shadow, the hypotenuse of the shadow, and the hypotenuse of the reverse shadow. And let's round our answers to the nearest whole number. So let's go ahead and draw a picture. And remember, these come from the shadows of vertical or horizontal nomans. So we can make both of those the radii of a circle. So we have a central angle of 30 degrees, and the radius is 60. So this length OB is equal to 60. And that means this triangle OGB is a 30-60-90 right triangle, and so we know that GB is equal to 30 the sine. And now we have two sides of a right triangle, so we can use the Pythagorean theorem to find the third side, which is the sine of the complement, and we'll start calling it the complement sine. And the thing that's useful to notice here is that triangle OGB is similar to triangle OAD. And so we can use similar triangles. AD to OA is equal to GB to OG. We know that OA is the radius, so it's equal to 60. We found GB and OG. So we solve for the reverse shadow. We have another pair of similar triangles, OHB and OCF. And so we know that CF is to OC as BH is to OH. And since OC is the radius, and BH is equal to OG and OH is equal to GB, we can substitute in those values and solve for the length of the reverse shadow. And we can find the two hypotenuses by the Pythagorean theorem again. One last note. Indian mathematicians used the word shiva for the half-court. Arabic mathematicians treated this as a technical term and transliterated it, keeping the sound without worrying about the meaning. And in Arabic this becomes shiva. Now, the Islamic works on trigonometry began making their way into European consciousness during the Middle Ages, and so Robert of Chester, who lived around 1125, misread this as jaiib. So he could have done the same thing that the Arabic mathematicians did and treated this as a technical term and transliterated it as jaiib, which would have at least retained the etymological connection to the half-court. But rather than treating it as a technical term, he translated it, and this word jaiib in Arabic means bay, and in Latin this is sinus. And the complement of the sign is the cosinus.


The Water Abundance XPRIZE is the concept of essentially generating water out of thin air. At this stage of the game, we're down to two of the five finalist teams. This week, we're in Berkeley, California, where we're evaluating the technology of sky water, sky source. The beauty of our system is the integration between a standalone energy system and a standalone water system to make 2,000 liters of water from air using 100% renewable energy at less than 2 cents per liter. These atmospheric water generation technologies serve the needs for water insecure regions, especially after disasters. Whether it's Cape Town running out of water or Flint, this is happening more and more. It has been pretty intense, but it's really exciting for me to see water come out of our system because this is connected to real lives in the world. We're here on the big island of Hawaii today where we've kicked off testing with team JMCC Wing. Use the wind to generate electricity and water, so basically you can drop a container like this in the middle of nowhere, have water and electricity without any infrastructure. This is always my favorite part of being an X-Prize competition is to actually be here on the ground and seeing the team on their test site, all this work they've been putting in over the last year, year and a half, it's always super fulfilling. It's one of the great things about the X-Prize is inspiring and motivating these teams to come together and give it a try. Now we've got two teams in the competition and they have a shot at winning a million and a half dollars, but more importantly, solving the issue of water scarcity. So, this is the winning team. The winning team is... The SkySouls SkyWater Alliance. This X-Prize, looking at the atmosphere as a way to harness water, has profound effects in affecting billions of people in the future that are going to face water scarcity.


Hello and welcome to lecture number 38 of this lecture series on jet aircraft propulsion. You have in the last couple of lectures been introduced to the sub concept of ramjets and pulsejets. That is a very interesting concept altogether. Ramjets and pulsejets are very simple forms of aircraft engines and they are simple in the sense that none of these engines have any rotating components. That makes them extremely simple to construct and design. And the reason why they do not have any turbo machinery like compressors and therefore, turbines is the fact that some of these engines can in fact generate so much pressure ratio because of the ram effect which is what happens in a ramjet that you do not really need a compressor. And since you do not need a compressor you also do not need a turbine. So, that makes the whole engine very simple because you do not have rotating machines and that makes construction of a ramjet very easy and to some extent the pulsejets are also simple which we will see a little later. And the whole aspect of making a very engine simple is something that every engineer would dream of that if you have an engine which is very simple and can deliver the required thrust that is perhaps the best thing that could happen. Unfortunately, of course, there are certain limitations to some of these engine concepts like ramjets and pulsejets. The basic aspect is that some of these engines cannot generate any static thrust that is you cannot really take off with either of these types of engines because they require a certain velocity and therefore, a certain ram effect before which they can start generating thrust. And very soon you are going to see that ramjets have a certain performance curve which peaks at about mach around mach number of mach 3 and again after a certain mach number after that mach number the performance drops drastically which means that ramjets have a very fixed or certain design range of operation in terms of mach number during which it of course performs very well. And of course, ramjets and pulsejets have been used extensively not for civil aviation purposes, but they have been used for missiles. Pulsejets in fact were used by the Germans way back in 1940s when they had one of their bombers which was very successful and the allied forces were very much affected by the German use of pulsejet based bombers like the V1 bomber and so on. So, these aircraft which were operational 50 years back were very successful in those days, but of course, they have lot of other issues which have not which needs to be resolved before which these engine concepts can actually be used for civil aviation purposes. Ramjets have been used for a long time for missile applications and in fact, some of the missiles which even India has uses ramjets and some of the long range missiles would want to use ramjets because they are everything propulsion systems and because of which you do not need to carry an oxidizer. The only requirement is that these ramjets will have to be first flown to a desired speed before which the ramjets can actually start operation operating which means typical missile configuration would have a rocket system which takes the ramjet the whole engine to a certain speed and then once the rocket has or once the missile has attained a certain Mach number at which the ramjets can begin to generate thrust, the ramjets can take over and then continue to operate like a pure ramjet missile system. So, the advantage of course, is that it gives you very long range because you can carry extra fuel in the missile and you do not need to carry an oxidizer unlike a rocket based propulsion system where you also have to carry an oxidizer that puts a lot of restriction on the amount of fuel that can be carried as well as the amount of payload that can be carried. So, these are some of the advantages that ramjets have pulse jets also have certain inherent advantages at the same time they also have disadvantages basically because pulse jets make use of certain valves if it is in the valve configuration there also valve less pulse jet configurations which we will take up for more discussion in the next class. So, in valve pulse jets which have been popularly used there are certain valves which operate and as a result of valves which are of course, mechanical devices there are a lot of issues associated with valves the operation of valves and synchronization of the valves with the whole engine cycle and so on. And therefore, the efficiency actually comes down as a result of these mechanical issues. So, what we are going to discuss in today's class are basically the thermodynamics of these two engine concepts the well they are not really concepts anymore they have actually been demonstrated in their operational. The basic thermodynamic cycle of ramjets and the pulse jets and also we will look at the cycle analysis of two of these engine types the ramjets and the pulse jets both the ideal cycle as well as we will look at the real cycle analysis in some detail. And so, this is what we are going to discuss in today's class and subsequently in the next class we will take up little more details of the components that constitute these engines like the ramjets and the pulse jets. So, today's class is going to be basically a discussion on the thermodynamics and also the performance parameters of ramjets and pulse jets. So, we will look at the thermodynamic analysis and thermodynamic cycle in today's class. We will begin with the ramjets first and so just to give you some brief introduction which you are I am sure you would already have had in the last lecture when you were exposed to the ramjets and how ramjets operate and how pulse jets operate and so on. So, ramjet is as I said the simplest form of an air breathing engine the reason why I say it is simple is because it consists of only three components consists of a diffuser a combustion chamber and the nozzle. When ramjets are designed or by their very construction or the thermodynamic principles ramjets are most efficient of obviously when they operate at supersonic speeds and in such very high speeds when the air is decelerated from a very high Mach number to very low subsonic Mach number it results in a substantial increase in static pressure and temperature which means that ramjets do not really need any compressors. Since they do not need any compressors you also do not need any turbines in a ramjets because turbines in an air breathing engine are meant primarily to drive a compressor in a ramjets you do not have compressors. So, you do not need turbines as well so this is probably the single most important advantage of ramjets besides the fact that they are air breathing engines that you do not need rotating machines and that is a substantial advantage both mechanical advantage as well as an aerodynamic advantage. Well the mechanical advantage is the fact that you do not need to carry so much weight and you do not have mechanical complexities of a rotating machine and the other advantage the aerodynamic advantage I would put it is the fact that since you do not have rotating components you can actually operate the cycle at very high temperatures much higher than what one would use in a normal jet engine because you do not have rotating components and so higher the temperature as you have seen results obviously in higher thrust or thrust to weight ratio and also it can lead to slightly better efficiency thermodynamically but of course in actual ramjets the efficiency is significantly affected by the presence of shocks through which the flow is decelerated in the intake. So ramjets have a variety of advantages but of course the major disadvantage is the fact that it cannot operate from zero velocity or it cannot generate static thrust which means an aircraft cannot take off on a ramjet engine it requires another form of thrust generation which can accelerate the aircraft to certain speed at which the ramjets can begin to operate and generate thrust so that is the single most glaring disadvantage of a ramjet the fact that it cannot generate static thrust. So let us take a look at a schematic of a ramjet you have already seen the working of a ramjet in the last class so ramjet as I said is a very simple engine there are only three components basically ramjets a typical ramjet would have a diffuser this diffuser could usually it would basically have two components one is a supersonic part of the diffuser and the subsonic part. We have already discussed about diffusers and intakes in a great detail in a few lectures where we had seen a typical supersonic intake will have two components one is the supersonic compression part that is what you see here where there is a spike or a forebody which generates the necessary oblique shocks to decelerate the flow. So, here there is a single spike which means that there could be one oblique shock and then there would be a normal shock after which the flow becomes subsonic. So, after the normal shock which under design condition or critical operation would originate from the lip of this intake and after the normal shock the flow becomes subsonic and then therefore, you have a subsonic compression taking place. Now, there is another counterpart of ramjets which you will probably discuss a little later in some of the later lectures that is known as the scramjet which is basically supersonic combustion ramjet it is very similar to ramjet, but combustion in a scramjet occurs in at supersonic speeds which means that you do not have a subsonic compression there flow is only decelerated through oblique shocks, but it is still supersonic and scramjets are designed to operate at very high Mach numbers above Mach 5 that is in hypersonic speeds. So, here the flow has to be decelerated subsonic speeds because in conventional combustors combustion stable combustion can occur only when the flow is subsonic supersonic combustion has its own limitations and lot of challenges associated with that. So, after the diffuser you can see the combustion chamber it is a straight through flow combustion chamber as you can see and let us say schematically we have few injection fuel injection system as you can see here fuel is injected and then how do you maintain the flame inside the combustion chamber. So, in order to maintain combustion a stable combustion we need water known as flame holders. So, flame holders are basically bluff bodies as you can see these are bluff bodies placed in the flow which means that in the downstream of the bluff body you would have a wake and the wake is a region where you have recirculating low velocity flow. So, these flame holders will act as devices which can allow combustion to be stable and there is a certain stable flame which is associated or attached to these flame holders. So, flame holders are meant to keep the flame in place and that you have combustion which is completed as much as possible within the length of this combustion chamber. So, the length of this combustion chamber will be decided by the fuel itself and the fuel particle size the spray droplet size because it is a certain length residence time as it is called required before which the fuel particles can completely ignite and combust. The last component of ramjet is a nozzle and the flow which the hot combustion products coming from the combustion chamber are expanded through the nozzle and this generates the required thrust by the ramjet. So, you can see schematically that at least in principle ramjets are very simple devices you have just three components here you have a diffuser, a combustion chamber and a nozzle. So, these three components put together generate a thrust which we have discussed in the last several lectures in a typical turbo jet engine requires much more complexity like it requires a fan or a compressor then a combustion chamber which is also there here and a turbine. So, a ramjet is able to produce thrust without using these other components. So, but the basic thermodynamic cycle of a ramjet continues to be the simple Brayton cycle. We have already discussed Brayton cycle in a lot detail we have also seen Brayton cycle as applied to jet engines like turbo jets turbo fans and so on. Let us now take a look at what is the thermodynamic cycle which constitutes a ramjet. So, ramjets work on the basis of the Brayton cycle for an ideal ramjet we are going to look at the simple Brayton cycle. So, the simple Brayton cycle as is shown here in this temperature entropy diagram consists of two isentropic processes an isentropic compression followed by a constant pressure heat addition or combustion. The third process is the isentropic expansion through the nozzle and since it is an open cycle the last process is the exhaust process. So, I have retained the numbering scheme which we have been following throughout the course. So, a is for the ambient 2 is for compressor or in this case just the compression exit for in the case of an a jet engine was turbine inlet here there is no turbine. So, that is the expansion beginning of expansion and 7 was nozzle exit. So, I have that is why you might wonder why I have put this numbering scheme of 2 and then 4 because we have just been consistent with what we have used earlier. So, in this ramjet the ideal ramjet cycle you can see there are two processes which are isentropic the first process which is the compression process and also the last process which is an expansion process through the nozzle the combustion process is at constant pressure. Now, we will first analyze the ideal ramjet cycle ideal ramjet cycle is one where there are no irreversibilities which means there are no pressure drops taking place efficiencies of components etcetera we are going to neglect and once we neglect some of these assume that some of these irreversibilities are absent then that cycle is basically an ideal cycle. We have already discussed ideal cycle of turbo jets and turbo fans and so on. So, in this ramjet cycle for an ideal idealized version of this ramjet cycle there are no irreversibilities in the intake which means that the compression process is isentropic there are no frictional losses no shock losses etcetera the heat addition occurs at constant pressure which means there are no pressure losses occurring in the combustion chamber and also the expansion process through the nozzle is again assume to be isentropic. So, with these assumptions in mind let us now carry out a cycle analysis of a ramjet and so we will be able to now derive expression for the thrust and fuel consumption that a typical ramjet would generate. And then subsequently we are going to take up a real cycle we will also see what are the efficiencies and pressure losses etcetera that need to be incorporated to get a realistic estimate of the performance of a ramjet an actual ramjet. So, in this ideal cycle analysis obviously we are going to use the isentropic relations because the compression and expansion processes are isentropic. So, we can very safely use the isentropic relations to determine properties in a performance in a ramjet. So, let us begin with the intake. So, in an intake we have the stagnation temperature T 0 A which corresponds to the stagnation temperature of the ambient condition T 0 A by T A is the stagnation temperature to static temperature ratio this is related to the Mach number by the isentropic relation. So, T 0 A by T A is 1 plus gamma minus 1 by 2 m square. Now, since the there are no heat losses or it is an isentropic compression which means it is also adiabatic. Therefore, T 0 A is equal to T 0 2 and so we get T 0 this right hand side is also equal to T 0 2 by T A. Similarly, for the exit we have T 0 E by T A is equal to T 0 7 by T 7 that is 1 plus gamma minus 1 by 2 m E square and that is also equal to the nozzle entry temperature because it is again an adiabatic expansion. So, we have T 0 4 by T A. Similarly, we can also write the pressures T 0 A by P A is 1 plus gamma minus 1 by 2 m square raise to gamma by gamma minus 1 and P 0 7 by P E which is the exit static pressure is 1 plus gamma minus 1 by 2 m E square raise to gamma by gamma minus 1. So, what we see here is that we can from the above equations we can basically infer that P 0 7 by P E is equal to P 0 A by P A. Now, if that has to be true then we should have the exit Mach number which is m E equal to the flight Mach number m. So, m E is equal to m which is also equal to U E which is the exit velocity which is since Mach number is U E by A E we have U E is equal to A E by A which is speed of sound at the exit divided by speed of sound of the ambient condition multiplied by U which is the flight speed. This is equal to square root of T E by T A multiplied by U and that is T 0 4 by T 0 2 multiplied by U. So, the exit velocity we have now expressed in terms of the stagnation temperature ratios T 0 4 by T 0 2 and the flight speed. So, exit velocity is now expressed as a function of these we will further simplify a little later we now go to the combustion chamber or the combustor. So, in the combustor as we have done even in the other cycle analysis for the jet engines the other forms of jet engines we basically carry out an energy balance across the combustion chamber. So, for the energy balance we have the incoming air which is coming in at from the after the compression process with a certain enthalpy then fuel is added with a certain enthalpy or heat of reaction. So, this sum of these two will be equal to what is going out of the combustion chamber that is the exit enthalpy. So, that from this we can actually find out what is the fuel to air ratio that is used or required for developing these temperatures or for developing these enthalpies. So, let us carry out the energy balance here for the combustor we have m dot which is mass flow rate of air multiplied by the enthalpy at the inlet that is h 0 2 plus m dot f which is the fuel flow rate multiplied by heat of reaction q this is equal to m dot plus m dot f multiplied by h 0 4 which is the enthalpy at the exit of the combustion chamber. So, we simplify this we have h 0 2 plus f which is m dot f by m m dot into q q corresponds to the heat of reaction of the or calorific value of the fuel that is used this is equal to 1 plus f into h 0 4. So, enthalpy we know is C p times the corresponding stagnation temperature. Therefore, C p into t 0 2 plus f into q is 1 plus f C p t 0 4 this is again simplified in terms of f we have f is C p t 0 4 by C p t 0 a is equal to or C p t 0 a is also equal to t 0 2. So, we have written it as t 0 a minus 1 divided by q by C p t 0 a minus C p t 0 4 divided by C p t 0 a. So, here t 0 a is also equal to t 0 2 because it is an isentropic compression there is no heat loss occurring in the intake. So, this is the energy balance for the combustor we get the fuel to air ratio from this energy balance. Now, we can calculate the thrust. So, the basic thrust equation as we have seen is m dot into 1 plus f into u e minus u plus of course, there is the pressure thrust term here we have already assumed that the static pressure exit is equal to ambient pressure. Therefore, p is equal to p a and therefore, the pressure thrust term is 0. So, the thrust per mass flow or the specific thrust is f by m dot is 1 plus f into u e minus u. Let us express u e in terms of Mach number and temperature u e we have already seen is u into square root of t 0 4 by t 0 a which is equal to u into square root of t 0 4 by t a square root of 1 by 1 plus gamma minus 1 by 2 m square because t 0 a by t a is 1 plus gamma minus 1 by 2 m square. So, we substitute this in the thrust equation and get a simplified expression for that and. So, if we simplify we can rewrite the thrust equation as f by m dot which is the specific thrust is equal to Mach number m into square root of t gamma r t a this multiplied by 1 plus f into u e we have just now rewritten and that is square root of t 0 4 by t a into 1 plus gamma minus 1 by 2 m square raise to minus 1 by 2 minus 1 and the other expression that is u is what is written here as m into square root of gamma r t a. Similarly, once you find out thrust you can also find out the thrust to fuel or the thrust specific fuel consumption which is the fuel flow rate fuel to air ratio divided by the specific thrust this gives you the T s f c or thrust specific fuel consumption. So, this is the basic cycle analysis which we have done a few times even in the earlier lectures when we talked about cycle analysis for jet engines like turbo jets turbo fans and all that. So, the same procedure was employed there, but there is a slight difference here in the cycle analysis procedure as compared to what we have done earlier on basically because at least for the ideal cycle we have here the exit Mach number is equal to the ambient Mach number and therefore, the corresponding simplifications in terms of the exit velocity in terms of the flight speed and that is how the thrust equation gets slightly modified and it is slightly different from what we have seen in our earlier analysis. One of the reasons of course, for that is the fact that most of the ramjets will have a convergent divergent nozzle unlike in let us say a turbo fan engine where it could be simply a divergent nozzle. So, the flow could be choking just at the nozzle exit and so on. In a c d nozzle also the flow could be choking, but then the exit conditions are basically if it is a fully expanded nozzle then the exit static pressure and the ambient static pressure are equalized and so on. So, the analysis of course, will the cycle analysis procedure might be slightly different depending upon what kind of an engine we are dealing with and also the flight conditions under which the particular engine is operating and so on. So, this is the basic cycle analysis procedure for an ideal cycle. We are going to now slightly modify this analysis for a real cycle where we are going to account for some of the losses that are likely to occur like the total pressure loss in the intake in the combustion chamber and the nozzle. So, some of these losses are and of course, the efficiency of the intake, the efficiency of combustion and nozzle and so on. So, all these performance parameters will now be taken into account to derive the cycle analysis for a real ramjet. Subsequently, we will I will just show you one typical variation of thrust as well as specific fuel consumption with Mach number for a ramjet. So, we will discover a few interesting aspects when we take a look at those performance characteristics. So, let us proceed towards an actual ramjet a real ramjet. Real ramjet as I said will have all these irreversibilities pressure draw up efficiencies and so on. So, one of the irreversibility will be the pressure recovery of the intake which is denoted by pi D that is P 0 2 by P 0 A for an ideal cycle this was equal to 1. There could be pressure loss in the combustor which is pi B P 0 4 by P 0 2. You may also have stagnation pressure ratio in the nozzle which is the nozzle pressure ratio P 0 7 by P 0 4. So, the overall pressure ratio is basically the product of the 3 P 0 7 by P 0 A is pi D times pi B times pi N ideal cycle would have this ratio as equal to 1 in a real cycle it will not be 1 it will be less than 1. So, this is how a real cycle of a ramjet would look like a real ramjet would have irreversibilities in all the processes. If you take a look at the first process which is the compression process you can see that there is a loss in or it is non isentropic process A to 2 is non isentropic compression. The second process was a heat addition in the combustion chamber here of course, there is a pressure loss occurring you can see P 0 2 and P 0 4 are not the same. Whereas, for an ideal cycle they were the same pressures it was a constant pressure combustion here it is no longer constant pressure. The third process is the nozzle expansion process which is again non isentropic. So, you can see that this process is also non isentropic that is process between 4 and 7 is non isentropic. One may also have a difference in the pressures the nozzle may not be fully expanded which is why one may have a difference between these two pressures P 7 and P a may not be the same which was not true for the ideal cycle where both these pressures were the same. So, this is how a real ramjet cycle would look like. Now, let us go to the cycle analysis of this. So, the exhaust mach number we are going to relate it to the inlet mach number with this expression that is M e square the exit mach number is 2 by gamma minus 1 multiplied by 1 plus gamma minus 1 by 2 M square this multiplied by the pressure ratio that is pi d pi b pi n and P a by P e this raise to gamma minus 1 by gamma minus 1. So, if in this expression we equate this that is expression that is if the pressure ratios were equal to 1 pi d pi b and pi n are equal to 1 and P a and P e are the same then what would we get we basically would get the fact that these mach numbers M e is equal to M. So, if M e is equal to M then this means that it is an ideal ramjet cycle like we have discussed earlier. For an actual ramjet the exit mach number is not going to be equal to the flight mach number there would be a slight difference between the flight mach number and the exit mach number which is not the case in this case which would happen only if these parameters that is pi d pi b pi n were same and equal to 1 and P is equal to P a. So, the second aspect is the fuel to air ratio. Fuel to air ratio we basically calculate by energy balance like we did for the ideal cycle the same energy balance is valid here except the fact that in this case we also have an efficiency of the combustion associated with the fuel addition. So, the air that is coming in has a certain enthalpy. So, mass flow rate multiplied by h 0 2 plus the fuel that is added that is m dot f into q which is the heat of reaction of the fuel, but this has a certain efficiency that is the combustion efficiency. So, that multiplied by eta b which is the combustion efficiency the sum of these two will be equal to what is going out of the combustion chamber which is the total mass flow mass flow rate of air plus mass flow rate of fuel multiplied by the enthalpy at station 4. So, if we do the energy balance we should be able to find out the fuel to air ratio the only difference between what is happening in an ideal cycle and ideal cycle is that here there is an efficiency of combustion coming in. So, if you look at the expression for the fuel to air ratio it is exactly the same except for a slight difference in an actual cycle of course, we will also be taking into account the variation of specific heat with temperature. So, you can notice that there is specific heat difference here for combustion products we will associate a specific heat which is let us say C p g this multiplied by T 0 4 divided by C p air multiplied by T 0 2 minus 1 divided by eta b which is the combustion efficiency into q divided by C p a T 0 2 minus the other product that is C p g into T 0 4 divided by C p a T 0 2. So, this is the fuel to air ratio as applied for a real cycle. Now, we also know that the temperature ratios T 0 7 by T 7 is equal to T 0 E by or T 0 4 by T E because there is no again we can assume that there is no loss of stagnation temperature in the nozzle that is true even for a real cycle this is equal to 1 plus gamma minus 1 by 2 m e square. Now, the exit velocity u is also related to the Mach number m e times square root of gamma R T E this we can simplify and how do we simplify that we can simplify that by adding or expressing T E in terms of the temperature ratios. So, we have m e into square root of gamma R T 0 4 multiplied by T E by T 0 4 which is basically expressed in terms of the Mach number. So, m e square root of gamma R T 0 4 divided by 1 plus gamma minus 1 by 2 m e square. So, based on this expression for the exit velocity where we have express the exit velocity in terms of the stagnation temperatures and the Mach number we can now proceed to calculate the specific thrust which we have the formula for specific thrust does not change it remains the same.  So, u e you can calculate based on what we have just now derived and once you substitute that expression for u e there you get an expression for the specific thrust and therefore, one can find the specific thrust and there and hence the the fuel consumption that is T S F C thrust specific fuel consumption. So, of course, I have not written down the expression for specific thrust because that is that will become a pretty lengthy expression if you were to substitute for the equation for u e it becomes rather complicated. So, the procedure is still the same as what we have followed even in the past.  So, if you substitute for u e here and also express u in terms of the Mach number and temperature one can express the specific thrust in terms of known parameters and thrust T S F C is basically the fuel to air ratio divided by the specific thrust. So, this is the basic procedure for calculating or carrying out cycle analysis real cycle analysis which is as you have seen very identical to the ideal cycle analysis as well, but of course, we have the performance parameters which have been included in this particular cycle analysis. So, what we will see next is that if let us say we have these performance parameters known and we were to calculate or determine the performance of a ramjet in terms of the thrust and the fuel consumption with Mach number, then we will see how the performance is going to vary. What happens as Mach number changes and how the performance of a typical ramjet is likely to vary, we will take a look at that and how basically the performance changes as we change the combustion temperature that is T 0 4 with increasing combustion temperature what happens to the performance of a ramjet. So, what I have plotted here is a rather simplistic expression or view of what really happens as the performance changes with Mach number. So, on one axis we have that is the y axis we have the specific thrust as well as the fuel consumption that is in terms of TSFC and the x axis is let us say Mach number. So, the solid line that is shown here is the specific thrust and the dotted line is the TSFC. So, for a typical Mach number the performance is going to vary like this where it is initially 0 and why should it be 0 for a ramjet as we have seen is an engine which cannot really generate a static thrust. So, for 0 Mach number very low Mach numbers the thrust developed by the ramjet is 0. So, there is no thrust developed at low very low Mach numbers or 0 Mach number it cannot generate any static thrust which is why an aircraft cannot really take off with a ramjet on its own. So, with increasing Mach number you can see the performance the thrust developed by the ramjet increases, but it reaches a certain peak and this peak is usually around Mach number of 3 to 4 it somewhere between 3 and 4 after which again the performance drops and at a certain Mach number which is a very high Mach number it will eventually become 0. Now, the reason for this drop in performance after a certain after the peaking performance is because of the fact that in a ramjet we are decelerating the flow from supersonic Mach numbers to subsonic Mach numbers combustion in a ramjet occurs at subsonic speeds or therefore, if you have if you have noticed as you decelerate the flow across from very high Mach numbers to very low Mach numbers the stagnation pressure loss becomes substantial which is why after a certain peak the thrust developed by the engine starts dropping because the stagnation pressure loss across the intake across all the shocks will start dropping and it becomes significant that very high Mach numbers that the thrust developed eventually becomes very very low. This is the reason why beyond a certain Mach number ramjets are not really efficient anymore and one would need to go for an engine which can actually afford to have supersonic speeds in the combustion chamber and that is why we have scramjet engines where combustion occurs at supersonic speeds and in a scramjet engine one would not decelerate the flow to subsonic speeds the flow continues to remain supersonic and therefore, scramjets are supposed to operate efficiently even at very high Mach numbers. So, this is how the specific thrust is likely to vary for a typical ramjet with increasing combustion temperature which is T 04 the graph that is shown here the trend is going to go up that is it will generate higher specific thrust. The other performance curve that is shown here is for TSFC you can see that TSFC initially could be very high that is basically because the thrust is very very low it is close to 0. So, the TSFC will drop as the performance as the thrust increases as the thrust peaks and reaches its maximum that is when one would likely to have a very low value of TSFC and then it continues to remain very low after that. And again with increasing combustion temperature the TSFC graph also would shift upwards because you would need higher fuel to generate higher and higher temperatures and that is why this curve is likely to move up. Now, if you were to carry out a cycle analysis for a real cycle as well as an ideal cycle what you will observe is that both the cycle analysis will give you very similar results in the sense that the trend would be exactly the same just that the graph would be displaced slightly for an ideal for a real cycle the thrust would be slightly lower than what it is for an ideal cycle. And fuel consumption is likely to be slightly higher than what it is for an ideal cycle that is because of the fact that in a real cycle one would have all the performance parameters put in like the pressure losses and efficiency and so on. And so for a real cycle one would actually get slightly lower thrust than what is predicted by a real cycle analysis. And the other hand you would also end up spending little more fuel because of all the losses that are taking place than what it is predicted by an ideal cycle analysis, but the trends remain identical. So, what we have seen so far is ramjet cycle its performance for an idealized version of the cycle ideal cycle as well as the performance of a ramjet when you put in all these parameters like pressure losses efficiency and so on. And we have also seen how the performance would change as one changes the Mach number that is that there is a certain Mach number at which the performance of the ramjet becomes or the thrust developed by the ramjet reaches its peak beyond which the thrust eventually drops and becomes 0. And which is why we have seen that ramjets cannot really operate at very, very high Mach numbers because of the fact that the flow has to be decelerated to subsonic speeds in the combustion chamber of a ramjet. So, if you can maintain supersonic combustion supersonic speeds then you are likely to be able to operate at very high Mach numbers and that is how a scramjet engine was devised and scramjets have supersonic combustion in the combustion chamber. And so for very high Mach number applications like beyond Mach 5 or so scramjets have to be used ramjets cannot really generate thrust for operation at these speeds. So, we will now move on to our discussion on pulse jets you have already had some discussion on pulse jets in the last class where you have looked at the performance of a pulse jet well the operation of a pulse jet and how pulse jets basically generate thrust. So, today we will take a look at the thermodynamic aspect of a pulse jet we will look at a cycle of a pulse jet and also see how we can carry out a cycle analysis for an ideal pulse jet and a real pulse jet. And then see how performance of a pulse jet can be measured or calculated based on the cycle analysis. Now pulse jet as you have seen earlier and something that I discussed in the initial part of today's class is a very simple engine like a ramjet. Pulse jet basically consists of again very few components there are no rotating components per say pulse jets comprise of an intake, a combustion chamber and an acoustically resonating exhaust pipe you have seen how a pulse jet works in the last class. And here of course, the combustion occurs in pulses and the thrust that is developed also is pulsating because the combustion itself is occurring in pulses and that is why it is called a pulse jet. There are two basic types of pulse jet engines the valve type and valve less type which I think we will discuss in little more detail in the next class. There are also another class of engines which are being developed at least conceptually that is known as pulse detonation engine. And these engines are in research for certain specialized applications some of which we will discuss in the next class. So, let us now take a look at the thermodynamic cycle of a pulse jet. Now this is a typical pulse jet a schematic of a pulse jet and what are the different components which constitute a pulse jet. So, a pulse jet has an intake section and then there is a valve series of valves which are operated based on the cycle on the cycle itself. And now stream of the valve we will denote by the station number 2 and then fuel is added in the tail pipe just before well just before the tail pipe in the combustion chamber. And then the combustion products are exhausted through the tail pipe and so the thrust developed by a pulse jet is basically occurring when the valves are closed and fuel is added in the combustion chamber. And there is a certain instant of time when it fuel addition or heat addition occurs in a constant volume mode. And then that is when the combustion products are exhausted through the tail pipe leading to a certain thrust. And then the cycle is of course repeated to achieve thrust in a certain pulsating manner. So, thermodynamically we will take a look at how the cycle analysis well cycle of a pulse jet would look like. Well pulse jet as I said will consist of an intake and an intake is where part of the intake you can see was constituting of these valves that we have seen just now. And inside the valves operate in sequences that is in certain part in some part of the combustion process that is occurring the valves are closed that is when the fuel is added in the pulse jet. And when fuel is added fuel is added at constant volume here and as fuel is added there the combustion products are eventually exhausted through the tail pipe. And the next cycle again the valves are open air is drawn in through the intake and this cycle is repeated. So, in the intake we basically for the ideal cycle of a pulse jet we are going to assume that the stagnation there is no stagnation pressure loss in the intake part of the pulse jet P 0 1 will be equal to P 0 a. So, that is what you see here P 0 1 is equal to P 0 a. And that is the static pressure ambient static pressure multiplied by 1 plus gamma minus 1 by 2 m square raise to gamma by gamma minus 1 this basically from the isentropic relation for an ideal pulse jet we are going to assume that it is an isentropic process. Now, for the similarly the temperatures can be expressed the temperature stagnation temperature is going to be the same T 0 1 is equal to T 0 a which is T a multiplied by 1 plus gamma minus 1 by 2 m square. And then for an ideal pulse jet we are going to again assume that P 0 1 there are no losses across the valves P 0 2 is equal to P 0 1 and T 0 2 is equal to T 0 1 and combustion as I said occurs at constant volume because it is an ideal cycle. So, an ideal cycle wherein the constant volume process. So, at the exit of the combustion chamber we have P 0 3 equal to P 0 2 multiplied by T 0 3 by T 0 2 because it is constant volume. So, from the state equation we have P 0 3 related to P 0 2 and the temperature ratios. Now, in the combustion chamber we can also have the energy balance we have done this a few times earlier already. So, this is the enthalpy of the stream exiting the combustion chamber which is m dot plus m dot f into C p into T 0 3 this is equal to m dot into C p into T 0 2 the incoming enthalpy plus the fuel flow rate. So, if you simplify this we get f which is the fuel to air ratio that is C p T 0 3 minus C p T 0 2 divided by q minus C p T 0 3. Now, in the tail pipe we will assume P 7 which is the exit static pressure is equal to the ambient static pressure and T 0 3 by T 7 is T 0 3 P 0 3 by P 7 raise to gamma minus 1 by gamma. So, the exit velocity can be calculated from again the enthalpy balance across the tail pipe we get U e which is the exit velocity is equal to square root of 2 C p T 0 3 multiplied by 1 minus P i by P 0 3 raise to gamma minus 1 by gamma. So, once we calculate the exit velocity you can also calculate the thrust and specific fuel consumption.  So, once you calculate U e you can calculate thrust and also the specific fuel consumption. So, this is the basic cycle analysis for an ideal pulse jet we will now take a look at how a real pulse jet would be operating in very brief we are now going to do the analysis in detail because we have already done this for ramjets and several other cycles the process is very much the same. So, in a real pulse jet engine where we are going to incorporate all the irreversibilities. So, this is how a real pulse jet cycle would look like the first process is again it was always non isentropic even in the ideal cycle in the cycle we are going to assume the stagnation pressure losses occurring between process A and 2. The second process is in the ideal cycle it was a constant volume process here in a real cycle they are going to be certain amount of pressure losses taking place it may not be anymore a constant volume process it would be a non isochoric process. The expansion in the tail pipe is again non isentropic as compared to the ideal cycle where it was indeed isentropic. So, this is a real pulse jet cycle expressed on a T s diagram and how does it differ from the ideal cycle well there are pressure losses in the diffuser given by P 0 2 by P 0 A in the combustion chamber and the tail pipe and therefore, there is an overall pressure ratio which in an ideal cycle was equal to 1. And the other difference is that in the combustion chamber we are going to assume an efficiency for the combustion products. So, C p into T 0 3 minus C p T 0 2 divided by combustion efficiency into Q minus C p T 0 3. So, these are the irreversibilities which will need to be considered in an actual pulse jet cycle which was very similar to what it was in the case of an ideal well an actual ramjet cycle as well in a pulse jet engine the other difference or efficiency that might come into picture is the operation of the valves. And so, there is a certain efficiency associated with that process because it is a mechanical entity there would be a certain efficiency that needs to be considered for these as well. So, considering all these efficiencies and performance parameters one can have an actual pulse jet cycle which is slightly different from the idealized version of the ideal pulse jet cycle. So, with this let me quickly recap what we had discussed in today's class. In today's class we had basically looked at thermodynamic cycle and performance parameters of ramjets and pulse jet. We started today's discussion with ramjets, we had a look at the ideal ramjet cycle, the thermodynamic cycle of a ramjet and then we also looked at a real ramjet cycle and how we can incorporate performance of different components of ramjet like intake combustion chamber and nozzle. Incorporate that in the cycle analysis and get the actual performance of a ramjet. We also looked at how performance would vary with mach number for a ramjet and why performance of a ramjet peaks at a certain mach number and does not perform well at very low mach numbers and very high mach numbers. Then we then discussed in brief about the pulse jet engines we looked at their ideal cycle and also the real cycle which constitute a pulse jet and also in brief we have looked at how performance can be analyzed for ideal as well as real pulse jet engines. We will continue this discussion in the next class. We will take a look at some of the components which constitute the ramjets and pulse jet. We look at the intakes combustion chambers and also the tail pipe and nozzles which constitute ramjets and pulse jets. So, we will take up some of these topics for discussion during the next lecture.


WHO urged for an extension of screening and testing due to the widespread presence of the coronavirus SARS-CoV-2. As such, a rapid and reliable diagnostic method is required. We developed a reverse transcription loop-mediated isothermal amplification, RT-Lamp, assay to detect SARS-CoV-2 in 30 minutes. For sets of primers were designed, targeting the viral RNA of SARS-CoV-2 in the regions of ORF1AB, S-gene, and N-gene. A colorimetric change indicated the presence of viral RNA, allowing for easy visualization of results. The assay was tested on 16 clinical samples, with 8 positive and 8 negative results. The test results were consistent with those obtained using real-time quantitative polymerase chain reaction, RT-QPCR. Additionally, we demonstrated that the RT-Lamp assay could be performed without RNA extraction, making it suitable for use in remote locations. This rapid, reliable, and cost-effective RT-Lamp assay provides a promising solution for. This article was authored by Wei Yi Huang, Boon Lim, Kieh Chen Hsu, and others. We are article.tv, links in the description below.


It more or less also expresses the good cooperation we have between Interpol and Europol also while seeing the actual situation in the world especially in Europe something is needed. That's also the reason I think both directors and Secretary General took up this responsibility and together within four weeks we were able to organize this conference. Well the purpose of the conference is to build up on trust, to find ways to exchange information on a global scale and also try to reach the position in which we really can start our investigation. So the outcome would be on trust building, information sharing and also real operational activity. Illegal immigration has already been a priority for us for a very long time but as of the situation we started up something that's called Jod Mahra that's a dedicated group of Europol and members of 12 different countries in trying to improve the information flow. Out of this, even because of the situation, the European Migrant Smuggling Centre will be built up. We will have additional staff of 30 people coming towards this and trying to make sure that we are able to give intelligent notifications to have a view on suspicious thresholds but also start up an investigation and support them. We need the information coming from not only from law enforcement but also working together with private partners with NGOs but also especially getting information from those who are being treated badly and being shifted around to Europe and other places. So in combining this information also using the open source activities I think we are able to get a better intelligence picture and we need Interpol also there for this because they are our gateway to the rest of the world. We are focusing on Europe and some third countries but in working together I think we can at the end get a better intelligent picture also.


So I was seven years old when 9-11 happened. Miss Coasey's second grade classroom. Tell most of my chiefs that, and they lose their minds a little bit. They're a little angry. They were Lance Corporals at the time. But in that classroom, we were watching TV. And then we were watching TV anyway. My teacher switched over the channels after she heard what happened. We saw what was happening on the news. We didn't really understand what was going on, me being my second grade classmates, I guess. Everybody started getting picked up early, so we thought something was going on. But we didn't understand. We were seven years old. My dad came and picked me up. He was a firefighter in town. He picked me up. My mom met me at home. And then he went away for about three weeks. Bound out later, he went across the river right over New York City. We grew up in Clarkton, Jersey. It's not a far drive. But he went over to Brooklyn to start cutting up the trucks, fire trucks, FBI vehicles. And they were told to look for the black box. Like three weeks later, he came back. He was definitely upset. Definitely agitated. There was a vigil in town for 9-11 happening. I still didn't know what was going on. I was eight years old. About a year later, he finally explained what it was, what they did, who they were, why they did it, and what some people called Marines were going to go do about it in Afghanistan. Kind of grew up always watching the news, seeing Afghan reels, seeing what was going on. And seven, eight, nine years old, Iraq popped off. And I was in fourth grade, the invasion, and you see more of those clips on the news. I definitely feel like I wanted to join because of what happened on 9-11. I didn't want anybody doing that again in this country. Further down the road, still, my dad is actually suffering, it's called frontal of dementia. It's not a very popular disease. But it's associated from the PTSD, from what he did at post 9-11, just finding bodies, finding people. But I don't think he would have had it any other way. He always kind of wanted to be of service, even with the dementia. The last few sentences he'd normally say were like, how can I help? It's just what he was in his nature. And then here we are today in 2021, 20 years later. And I don't think there's many today that grew up in a post, or grew up in a world without 9-11.  I was already a kid at the time. I got to experience before and after. It's not a luxury many have. Many of the Marines I work with were either already born a few years older than me, or are younger than me, and it's a weird generational gap to try to convey what it was on that day. I've never seen more American flags on the street in my entire life than September 12th, 13th, 14th.  It takes you back to like 9-12 or any day after 9-11. It was a pretty amazing time to be an American, despite tragedy. It's amazing how we can come together so quick after something so devastating.


Hello, everyone. Nice to see you here. I'd like to thank Jack, Byron, Judy, the friends of San Francisco Public Library for their continuing efforts for our community. I recently saw a very moving and inspirational film called Red Poet. It's about Jack Hirschman's wonderful life as a poetry. If you haven't seen it, you can catch it on YouTube. Please enjoy Red Poet. My piece is about my visit to Japan last November. Coming home, viewed through the window of a blood train heading south, Mount Fuji half hidden, the snow covered peak piercing the clouds. The Pacific coastal mountains of my hometown, Shizuoka, around and gentle, bamboo forest undulating in green waves. At the cemetery, in back of an old temple, stood a familiar tombstone. I poured spring water over my ancestors, offered yellow chrysanthemums, and burned incense in prayer. He'd get lost walking away from home, would fall on the street. A few times would be taken by ambulance to a hospital. My siblings warned me of my big brother's Alzheimer's. He may not recognize you. Three years before when I saw him last at our niece's wedding, he seemed hearty and robust at 73. Two months later, his wife died unexpectedly of a heart attack. I approached big brother's door through the bonsai garden of pine and plum trees. Once his pride and joy now overgrown with dry tall grass. Oh, Toshi, he said, standing at the doorway, uncertain. Thin and feeble, the loss of weight startling. Slowly, he seated himself at the kitchen table. From the heap of food packages, pill bottles, yellowing newspapers, and sundries, he pushed forward two mandarin oranges. Eat. Do you want tea? No, that's OK, I said, staring at the huge bandage on his forehead and his food-stained beige sweater. He pointed to a bundle of cars hung on the wall, large letters describing his daily schedule. Someone's coming to take me to the center today. Many old people there talking funny, some screaming. You think they are joking, but they are serious. I listened to them. He said, always a quiet man. He was unusually talkative that day, perhaps a good day. He recalls some 20 years before when we soaked in a hot spring deep in the mountains on the Izu peninsula. Big bubbles, you farted. He said, smiling for the first time. Soon, he led me to the family altar in the living room. Framed photo of his wife and young son prominently displayed. I burned a candle and incense and prayed to his long departed beloveds. My wife died yesterday. My boy was only 27. That's life, isn't it? He muttered. I held him in my arms and whispered, you take care. You take care, too, he said firmly this time. A late afternoon train left my hometown, farther and farther behind. Deep orange specimens growing here and there on darkening hillsides. What else could I do but to carry their memories? I kept looking back. No, thank you very much.


So what is it that makes this nation tick and go? Those who look at us from outside think we are an impossible chaos.  If only if we can take a few steps, a strong steps in the next few years, what is possible is truly tremendous. Nations are made because of sameness of race, religion, ethnicity, ideologies, languages. But in that sense, India is in defiance of all those things. This is a total defiance of the sameness. If you just go fifty-hundred kilometers, people look different, speak different, dress different. Of course, eat different. Everything is different. But for over ten thousand years, we have been a nation. Even when we were ruled by over two hundred different entities, political entities of the time, still we were called a nation. Not only by ourselves, but the rest of the world also looked at us as a nation, even though politically we were over two hundred entities. So what is it that makes this nation tick and go? Those who look at us from outside think we are an impossible chaos. But our chaos is like if you compare a manicured garden with a forest, those who lived in manicured gardens will feel lost in a forest. But if you don't tend to the manicured garden for a month, it will be no garden at all. But forests have been there for millions of years. So what looks like chaos in the surface is a very resilient organization of its own. Not understanding this, a whole lot of people are trying to break that and bring a new, very synthetic level of organization to this country which will not work for us. In fact, we enjoy some chaos if we lost if there is no chaos. To make a nation, there are few fundamentals. Three basics are the territory of the geography is a fundamental thing. When it comes to geography, when we started forming this new India in 1947, we made the most fundamental mistake of breaking the geography into pieces, three pieces. Not understanding that this break will lead to a problem that could endure forever. In the sense I'm not here to give you a political commentary about what happened in 1947 or 48. The important thing is this has been a business nation forever. Political entities came and went, kings and empires came and went. But the business endured. We were the largest business on the planet. Columbus's Voskoti Gamas did not do daring, seafaring journeys just for adventure. They were looking for the largest economy on the planet. Well, we nobody talks about hundreds of expeditions which drowned in the ocean of course. So this was the largest economy and it stayed that way because it was a business nation. It was not a political nation, it was not a military nation, it was a business nation. But we forgot this and we broke both sides of the country which were our trading routes for thousands of years. Forever we had traded through these routes and we broke the trading routes and made a nation because we have a little blinded by our freedom. We broke the country and broke our trading routes and we thought we will somehow survive with our activism. Well, first forty-fifty years went about without knowing what the hell we should do with ourselves because by the time we understood that the by the time the leadership understood rather that to make a nation successful what is required is not successful politics, what is required is not successful armies, what is required is successful businesses. By the time we figured this out it was thirty-forty years gone. So now we have we can say this new upsurge in India is only about twenty-five or thirty years old. For thirty years I think we've done a great job. What do you think? We could have done better. We could have done better that is always in post-mortem. We could have done better but for thirty years for any nation of the size that we are and the complexity that we are we've done great but we are dragging our feet on a few things. As I said the first dimension of a nation is its territory territory or geography. The second part is the processes and systems the laws and mechanics of how a nation should function. In this we have dragged our feet a little bit and because of this we still have many systems and processes which were imposed upon us by the occupying forces where the fundamental intention was control and obedience. We still have many laws and many processes and systems which are all about controlling the citizenry not about unleashing our human prowess and genius and human intellect to function and above all India's enterprise to really be unleashed. Unfortunately we inherited a whole lot of them only now we are paying attention as to how we can change. We have been dragging our feet on this for this nation has paid a huge price. Though on one level we have the fifth largest economy as the prime minister was saying but at the same time we also have the largest number of malnourished children in the country. So we are both ways there are strides ahead and there are leftovers behind we are trying to pull them along but we have definitely dragged our feet on fixing the systems and processes which should which should govern this nation and the third the last but the most important is the people. In the minds and hearts of people if you don't build the nation there is no real nation. Nation is just an idea when we invest our thought and emotion into it it becomes a wonderful idea otherwise it becomes a nasty idea whether it's nation or a smaller entity of society called family. So for example marriage if you take it it's just an idea but if you invested your thought and emotion in it absolutely it could become a wonderful idea or it can become a horrendous idea. The question is only how much of myself will I invest in that idea the same goes for the nation how much of ourselves do we invest in this idea of nationhood accordingly it either becomes a wonderful idea or a horrible idea. We've been little back and forth on this because when we got our independence we did not do this aspect really well when we got independence there was a huge pride of being Indian. Slowly it got chipped away and worn out because we did not establish this idea strongly in people's minds and hearts. We did not do enough work on that we thought it just happens by itself because of this people took on their own small identities of caste, creed, religion, race, ethnicity all kinds of things. So we are a bit struggling on these things because we did not do we did not beat the iron when it was hot now cold steel to beat it we are struggling a bit to a point where some people are confused whether they belong here or somewhere else we have kept this confusions going unfortunately. I think it's time to settle because if this one thing if we don't settle that people are clear that I belong to this nation and the only way for me to prosper is to be a part of this and to make this work if that doesn't become clear in everybody's minds and hearts taking the nation ahead will be a struggle. So these three dimensions all these three we have to settle one thing is the geography or the borders of the nation has to be fixed and say this is it some give and take should happen and there should be no confusion for future generations as to which is India and which is not India. Whether I'm in India or I'm outside India it was be clear to me otherwise how will I focus my emotions and energies and how will I dedicate myself to something this confusion we have left this must be settled now for taking strong steps for the nation and the systems and processes it is very important that we explore every one of them and see whether this is made for free India or this is made for enslaving India in the sense just to give you a sample for most of you if you are from outside the country you may not understand this even today for most common people not criminals regular people even mothers tell this to children hey you you listen to me otherwise see the policeman is coming a policeman is not seen as help a policeman is not seen as support a policeman is not is giving you security policeman is a threat this is because this is a hangover from the british era policeman comes means your life is in trouble because he's always there to trouble you so these kind of things still exist we have to change these things that when we see a police officer or a government officer we must see solutions are coming not problems coming our way right now still most people experience this is a problem we have been dragging our feet on making policy changes drastic policy changes will will cause some upheavals but if we are not ready for going through that little pain that we have to go through when changes happen that means we will not make any change that means we will stagnate a whole lot of people telling me for example gst has hurt small businesses yes it has I know this very well because they are in all in touch with us and there is a lot of pain but if we don't make these changes forever this nation will be a small business if you want this nation to become a big business then we have to make some changes which are painful we are used to working out of our pockets just to trust this money that I trust my money only if it's in my pocket even the bank I'm suspicious this is how the culture has evolved because the governments that ruled us were always from outside for many centuries so we were always suspicious of them it is very important now the people of this generation and the future generation are very clear hearted about this that this is our country and these are our governments and these are standing for us not against us this has to become very clear in the minds and hearts of hearts of Indian people otherwise we will always be half hearted about what we want to do in this country and coming to the people we have 1.3 billion people really if you look at it that is our greatest strength and that could be our biggest problem but if we have 1.3 billion people who are well educated skilled focused and inspired we will do a miracle that nobody can imagine possible but if you leave them unskilled unfocused uninspired then this could be a recipe for disaster so this is where our real challenge is whether we will convert this human resource that we have into a phenomenal force or into a great problem for ourselves this challenge if it has to be addressed serious policy changes are needed so as a nation we are standing on a threshold will we have the courage and commitment to take the steps that will make us cross the threshold or will we just sit there lot of people have this thing no no we are on the right track i'm telling you especially if you're on the right track and sit there for too long you will get run over especially if you're on the right track so we don't become a runover country but we became a country which is on the right track moving at the right pace this is important as i said earlier this is in the hands of the business the political leadership can only set agenda can only make policy but the real nation happens depending upon how the business will buzz in this country well i know there are difficulties i know there are challenges there are problems of corruption there are problems of variety of things roadblocks all over the place but this is our time we can talk about glorious past it doesn't matter this is our time on this planet whether we will make this the greatest time in history of humanity or we will make it the worst time is all in our hands there are many challenges there are ecological challenges there are nourishment challenges there are organizational challenges there is investment challenges but the possibility is so big that these problems look small in terms of what is possible for this nation what is sitting in front of us is so big if only if we can take a few steps a strong steps in the next few years what is possible is truly tremendous above all as a nation we have been always a land of seekers not a land of believers seekers means we have invested in our ignorance understanding the intelligence of ignorance is very important if you identify yourself with what you know you must understand in this living cosmos what we know is a very puny little thing what we do not know or our ignorance is a boundless nature of boundless nature our ignorance is really boundless so we have always invested in this that is why this is a land of seekers in this is the root of this nation in this we evolved this nation in such a way our culture in this country where human genius unfolded because we were always seeking about things that we do not know this is understanding the intelligence of ignorance understanding that the phenomena of life is always on full fire if you are in a seeking mode if you come to a believing mode you settle down but when you're in a seeking mode you're continuously on fire so this fire we have exhibited for thousands of years we should not lose this fire because this is where our growth is this is where our future is


Hey everyone, this is Gabrielle with Oxmerata Group. I'm here today at Oxmer Toyota. I have Chuck Schumann here with me So Chuck and I are gonna go over a 2018. It's a Toyota Highlander now This is the SE which is more of the sportier model So Chuck if you could kind of start off on the exterior what's different on the SE that'd be great Yeah, absolutely. So the first thing that you're gonna notice is the grille so on the XLE Limited limited platinum all those. It's a silver grille. This has a blacked-out grille. It's a more aggressive look There's actually black accents around the lights which gives it a tougher sportier look This still has Toyota Safety Sense P just like all the other trims in the 18 highlander So you get lane departure, pre-collision pedestrian detection, automatic high beams, dynamic radar cruise control And then you also have a sportier wheels here as well for the you can spot this from across the parking lot And know that it's an SE. I mean these are very very cool And then the interior there's some changes as well. So you get a leather seat that's heated It also has like a racing inspired stripe there in the center like a racing stripe. So it's a sporty look It's aggressive and it all has all kinds of creature comforts in here as well. So there's navigation XM radio pair everything with Bluetooth. So very very cool. It's got a sunroof. I mean this thing It's similar to the XLE. It's just got some styling differences It does in that and you got great space back here for friends and family It always comes in captain's chairs when you get an SE. Okay So you get the captain's chairs here. They continue that racing stripe theme there in the back And just a lot of space you got a little console there. You got places for people to charge They can control their air in the back. It controls three-way air. So air in the back passenger and driver can all have separate Temperatures set to automatic which is really awesome and comfortable because not everybody runs at the same temperature right And then back here you've got a lot of great space so These seats fold down And you still have three seats in the back here for this third row and you got a ton of storage space You can also it's a 60-40 split so people can actually be in that third row and you can have a bunch of luggage stored as well So just a very Utilitarian, you know vehicle. It's fantastic. It is. Thank you so much. All right, you guys If you have any questions on this vehicle, please feel free to let us know So the best winner, but it's<PHONE_NUMBER> you can also visit our website It's oxmortwayo.com and I'll have a link to this vehicle in the comments below So thanks you guys for watching and we look forward to seeing you all soon. Bye Vegas


Shifting our focus to South Africa where the death toll from the devastating floods that have hit urban and surrounding areas has now risen to over 300 with many people continuing to be missing.  Recovery workers with dogs searching for bodies. 40,000 South Africans now displaced more than 4,000 homes destroyed. This is a sorrowful moment for the people of South Africa, especially the families that are still mourning their loved ones. When I arrived, when I came back from the clinic, it was a little bit early, like eight up to nine years. As I arrived, the only community was there with the two police. My wife and my son. You all know that I declared the year 2022 as a year of charity and the flood victims right here in Deban City will not be left out. We found someone who lives in the township where the flood happened but her house was not affected. How many places were affected in here? Almost every place. It just depends on how bad the situation was. But your house was not affected? So she took us to the camp allocated by the government for the people that homes were destroyed during the flood. When we got there, we met the ketika of the place and she told us that the people living here right now needs two things. That is food and accommodation. And what our strength can do for now was the foodstuffs. But with our accommodation, I think we're going to do it together as a family. We're going to put our strength together to build a home for them. Where do you live now? I live on top there. You don't have a place to stay now? You don't have a place to stay for your own? We both have I think over like 1.4 million subscribers. We will put a go for me link down in the in the description below. We like to build in a house. I just want to let you guys know something. Tayo and I are not doing this to show off, but it's something that we're doing just to inspire you. For me, if I'm not a YouTuber, like you would never see me doing anything like this on camera. But since I have audience, I have people like you who watch my videos all the time. I'm just trying to tell you that giving is not a crime. I would give just to inspire you to go out there and give that little amount of money to put smiles on people's faces. You know what? Do you guys want to shop with me? Or have you checked the link in the description? Click on it. If it's a dollar, let's donate it and give it back to the society. They need us. We are all Africans. It's Africans that are suffering. And I believe that you and I as Africans living in different part of Africa can come together and support our own time. It's now. Thank you. We're giving 15 items to buy. And on the list, there is tissue, so that it is. You don't know, right? All right. It's the South Africans love chicken feet.  No, for them. I saw the way you've been packing chicken. You've been packing too much chicken. Don't go and take it to your house. Where I live, I cannot even cook, man. Candles and matches. Apparently, where they live, there is no electricity. So they need candles and matches. I'm thinking with the government, man. I mean, electricity is something that I think each and every South African needs to have, right? So I guess maybe we're just going to buy this today. But I think maybe if you see this video, make it happen, yeah? Let them get electricity in there. Hey, yeah, yeah. Bro, this is from, isn't it made in Congo? Isn't it made in Congo? They chop it. Man, let me ask you. You know, we cannot have a serious conversation all the time. Which African country, man, do you think have this one? Leave that in the comment section. Do you want to know? Nigeria. Ah, no, I think Congo will win. I want to know what is this so important to you? It's important because, you know, we're all Africans. And if one African is going to a problem, then all Africans are going to us in problem. And if we can lend the helping hand to help people, then we should. So, you know what? It's time for you to join the movement. We are doing our part. So you also have to do your part. The link will be in the description. But yo, Tyre is amazing, man. I mean, if you're watching this video and you have not subscribed to Tyre, Ina, what are you waiting for? He makes the dopest African vlogs. I mean, let me finish. Let me finish. Let me finish now. He makes the best African travel vlogs. Go check out the description box. Subscribe to his YouTube channel. You watch my videos? Take me back to Ghana with you. I'm talking to Ghana. Yeah. Really? I hear Ghana is the best country in Africa right now. How did you know? I watched a lot of blogs from Ghana. Nice to see you. Nice to see you. You're from Deba. I'm from Deba, yeah. You heard about what happened. The flats. Yes, yes, yes. How bad it is. It's very bad. People are devastated because they've lost income. They've lost money. They've lost a whole lot of stuff. The homes, lives, it's bad. So, you know, so sad and I didn't know anything about it until I arrived in Deba. And then a lot of people were saying, this is the wrong time to be in Deba because, I mean, a lot of lives have been lost. You know what? I think the mood is low. Everybody's mood is not that great. But I think if you go to certain parts of Deba, you'll be fine. If I had time, I would have definitely joined you guys because I love your videos, my guy. I just wanted to shake your hand and know that I've met this guy in my life once.  What are you going to tell them? No, I'm just, it's one Africa. One Africa, yeah. I said, yeah, we're all together. This thing of people complaining, saying we are zoonophobic and people saying that, I mean, we all, we all won. We all won. I love you, bro. Thanks, my brother. Thank you. Yeah, yeah. Thank you. Nice to meet you. All right, man. Nice to meet you, too. It's time to pay for the bills. But we are lined up right now. It's like the person who is coming to serve us is like, what is going on? This is too much for one person. We're going to feed about 198 people. 198. So, I don't think this is, this is not enough. But we're doing our part, yeah. I'm one Niger, I'm one Niger, hey. I got my brother from Ghana, man. What are you going to tell them, man? Well, we are here to support a brother. We are happy, you know. We are doing this together. It's a great feeling, you know. I feel like it feels good to put smiles on people's faces. Yeah, you know. Oh, I'm so zoonophobic. I mean, I'm everywhere, you know. How are you? Nice to meet you, too. Yeah, you're from here? From Deba? From Burundi. From what? From Burundi. Burundi? Oh, nice. I follow you. Nice, it's good to see you. Wow. See, before I let you go, you may say to Africans. You see yourself. They must keep following you, listening to what you are doing. You are doing it. Might go to this side. Publishing the continent. Yeah. I knew them all the time. So the youth will know that it's not only about going in America or everywhere. Even here in Africa, you can make it. Here in Africa, you can make it. You can sell one? You can go over there. I see it. What I love about South Africa is that even in the malls, when you are filming, no one is coming to you to tell you that stop filming. Where I'm coming from, even your phone. You can't use it. Hi. You can't use your phone. They will tell you that stop filming me. Say hello to them. I told you, yeah. The South Africans are the nicest people you will ever meet. Oh my goodness. Well, this is the South Africa that most of you have never been seen on TV. So yeah, she's representing the real South Africa. We ended up tasting it there. I'll just try this one. Yeah, he already checked it. You know, in an African home, if I'm going to give something to somebody, you need to taste it first, you know? Cool to see United Africans coming together to solve a problem. So listen, this car belongs to a Ghanaian and this car right here belongs to my brother from Nigeria. And you know, she's from Swaziland. Come on, say hi. And we're all from different African countries coming together to solve one problem here. They decided to bring their cars, support us. We haven't even been buying the fuel. Like, I'm like, what are they doing this? And they just said one thing. We're all Africans. So listen, if we unite as one, we can do a lot of things. Yeah, I keep on telling you guys that two Africans, three Africans can come together to solve a problem. Enough of doing this individualism. You know, it doesn't take us anywhere. I'm so emotional. I don't want to cry because men don't cry. But yeah. Because men don't cry. You want to cry, bro? Because I just cried yesterday. For what? A woman broke your heart?  Because that's the only time men cry, man. Yeah. Anyway, I'll see you guys when we get there. So we finally got here. This is the place where the people that have been displaced by the flood are living right now. I think this is the place that was provided by the government, right? Yes. So who are the people that live in here? It's the citizens. Citizens that were affected by the flood, right? So people living here don't have a place to stay. Yes, they don't have anything. The flood wiped off their houses. Identity documents, everything. They have nothing. They have nothing here. So this is where they stay? Yes. So they tell us that we've got this one we're going to bring this to them. You know me? So, oh, you want to help me? Don't worry, yeah. Ah, thank you, my brother. Thank you. Thank you. You guys have more here? Yeah, I think in the seat. In the seat. Thank you. Thank you so much. Thank you so much. God bless you. Thank you so much. Let's me help Kevin, yes? This one? This heavy, can you carry it? Yes. It's your friend. Yes. Right. This one I will help you carry. Then carry buckets on top of there, just like that. Just like that. You know, when we used to go and fetch water in the village, this is how we carry the water. One here, and one there. Yeah, yeah, yeah. You go, come with me, let's go. To eight people living here. How many people live here? 198. 198 people live here. How many children? We have 65 children. And how many men? Dirty men. The rest are women? Yes. Which means you've got so many women living in here. How many people in Tarleton? Eight, 108. 108. 108? No. So which means, as everybody lives here, there's no privacy here? There's no privacy. There's no privacy at all. What do they sleep then? Point of correction, guys. Yeah. This is our sister. This is our sister. You, I can, I am live. This is our very important sister. We love her from our bottom of our hearts. We have to say thank you to her. Because all those things, all the food we're having, she's the one who's making this. I'm not going to forget my brother. Guys, we really appreciate it. This is night. I can't even mention the name of her. So guys, thank you very much. Thank you guys. We appreciate everything that you have done for us, even our volunteers. Thank you guys. We love you all. So, there's nothing much I can say. I'm going to cry. So it's like this puts smiles on people's faces. And we can do this together. So I just want you to understand that this is just one place and there are so many places in here that we can do. Together with them, we can raise funds for them. Thank you. Thank you. From Ghana. Yeah, Ghana and Nigeria. An organization or just- No, no, no, no, no, no organization. No organization. That's individual. You started in your working here. You could visit. We came to visit. We came to visit. And then we found- No, it's been three days now.  Because when we came, everybody started saying that Japan, this is happening. This is happening in Japan, right? And we are like, you know, we cannot go like that. We live in tomorrow. So we can just come today, do something, and then we'll go back tomorrow. So kind of. Thank you. I mean, we're all Africans. Yeah. So we need to suffer. Thank you all. I hope God will bless you guys. Thank you very much. That didn't catch your name. And- My name is Maya. Maya. Thank you, Maya. And your name is? Tayo. Tayo. Thank you very much, guys. We really appreciate your help. From people who were displaced by the flood, right? But people that lost their family because of- I mean, some of them are going to trauma, right? So because of that, they can't stay in there. So we are actually on our way to go and meet someone who lost family members. I hope I don't fall, man. This was creature by the flood. Yeah. The water is so cold. It rained at night or in the morning? What, at past nine? At night. Nighty. So they were sleeping? Yes, they were sleeping. So, I need to show you the place where we found the mother in the- This is the house. We found them there, next to the blue thing. Dead. The water was running through all the- We found them deep down inside the sand. So the- I mean, were they in the house when they happened to be here? No, they were four. Two of them, or they are alive. Two of them, they are dead mother and the son. They just break the wall and come out just to save. Because they had the mother or the wife screaming. They said, oh, my son, my son. Then they took the brick to try to break some. They are already on the downese. As you can see, it's wet here. Okay, they are so resting after this. So you are buried already? Yeah, they are. Yes. Yeah. These are toilets that they are using, these toilets. There's the line. That's the- when they are hanging your clothes. This, yeah, as you can see. So is anybody building the home for him again? No, from now he's living on the neighbourhoods. Or he's coming, she's calling him just now. So you can speak to him. I think, I mean, that would be better for us to- If we have to do anything, we have to maybe- If we talk to him, we can actually build for him rather. What does that mean? I just want to say sorry for your loss. Okay. And we know how you feel right now. But can you tell us what really happened? Yeah, it was Monday last night. When I started to sleep, two rooms were falling down with these two big rocks. It was coming on a- on a boundary here for my neighbour. As I started sleeping, the whole room was falling down. Falling down? Yeah. So the wall- did the wall fall on you? All of us. Because me, I was on a kitchen, on a- I was just sleeping on a sofa. On the couch. On a couch, yeah. My wife and my son and the- The other son? The other son was on a room. On a bedroom. And another bedroom? Yeah, another bedroom. As the wall is falling down, I'm just shouting, hey, we're just dying now. I see the small child, that one was here. This legally one. Was- only bricks here is- the head was inside the bricks and then the bricks was pushing like this. I was just moving the- the bricks on me and then I was just pulling my last son on the bricks. As I was pulling the last son on the bricks, there's another one there. He's crying, hey, Baba, just grab me. I tried to grab that son, but I never feel it. I was just touching only his hands like this. I just removed all the- all the rocks in the- in the bricks. As I was moving all the rocks in the bricks halfway, I just pulled him like this. Hey, it doesn't come. I just keep running to knock on my neighbors because my neighbors can't hear nothing because- because of the rain. I just knocked door to door, I caught three guys. One for the- for that grey house, one for other side, this side, and my neighbor on top here. He just sent me. We're starting to try to pull out this one, this son. Since ten, up to three, doesn't come out. As we're pulling out, it's inside the hole. This rock, we just waiting with the- with the- with the spade because if we- if it is moving, it's gonna- go down with the- yeah. On here, as we're pulling this one, on here, no one shouting, yeah. With my wife and my son, I wasn't shouting. As we finish to pull out this one, I say, hey, there's another two. Over there. Yeah, there's another two people here. I can't see them. Yeah. So this one, you managed to pull- Yeah, we managed to pull it. Where is he now? He's there. He's sitting there with no- oh. On top there. The one who broke his leg. Broken leg. Yeah, broken leg. Yeah. Hey, the one who broke his leg. So, who better now? And then, and then I take him to- To the clinic. To the clinic. As I take him to the clinic, the- my neighbors and the- Communities here. Community. He just- I can't see my wife. Can you please just search for my wife and my son? Yeah. He just- I'm taking them to the hospital soon. Mm-hmm. When you arrive, Katsu, where are you now? When I arrived, when I'm coming back from the clinic, was a little bit early, like eight up to half past nine. Yeah. As I arrived, all the community was there with the two bodies. My wife and my son. I'm taking my son to Arkeka. Coming back later. Hey, where I can just leave? I just go to my neighbor's. So, where do you live now? I live in Gontopu there. In the neighbors. You don't have a place to stay now? Sorry? You don't have a place to stay for your own? No, I haven't gone. Um, Taro, I think we can build a house for you. Okay, Baba.  I am suffering so much. He doesn't want you to rebuild the house. No, no, no, no, we can't. We won't rebuild this one from somewhere else. Yeah. Okay. There's just somewhere else. Okay. So, um, we're going to do this. Taro, I think, um, ha, feels so emotional. Wait a minute. Taro, you can go ahead, man. Let's just, Taro, just take over. Yeah, and, you know, here in this story, I'm sure as you guys know, as you're watching, it's like, it's really sad. And we can find a way to kind of like help out. And nothing, nothing we're going to do is going to bring back to people who are already gone. But at least people who are still living, we can find a way to help them. So, we both have, I think, over like 1.4 million subscribers. We will put a go for me link down in the, in the description below. We like to build a house somewhere else in Dublin so that at least we can start again, can have a new home, and start again. I'm like, I'm not sure the voice. No, I know. I know. So, um, let's, let's just do this together. Um, I believe that after this video, we're going to talk and then I'm going to tell you how much both of us can put together ourselves. And then we set the example so that you guys will follow. Uh, I'm going to come back here again Just for this project, we're making sure that we do it before we get out of there. Yeah, he said, if you want to say something. Thank you very much for your support. And we hope that soon you're going to do something better in you. Because now they don't have clothes for him and to his sons. And the more thing that's worrying us, the place to sleep. They're sleeping from neighbors. I don't know if they have food or they don't have food. So, guys, we need you just to be together. Like, now we're like family. Yeah, definitely. One hand touch another so we can come together as one. Thank you very much. Thank you so much for coming here with us. Thank you, papa. Thank you. Sorry for your lost year. We'll come back again. Hi. You watch my videos? Guy is here and he just said, what am I? Hi. What's your name? Fundi. How old are you? How old are you? Sixteen. Sixteen. Which video did you watch? But I know you. Alright, interested man. Let me... You have my bag. Give me my bag. That's the boy who watched my videos, man. Take it, huh? I've given all the money to you.