This 2015 Ford F-350 Crew Cab Short Box Single Rear Wheel is stock number 12265Z. We are here at Summit Automotive in Final Act, Wisconsin. You're new and used heavy-duty truck headquarters. This 2015 Ford F-350 has the 6.2-liter V8 engine. This truck has been fully-safetyed and inspected by our service shop for the state of Wisconsin inspection process. It has a fresh oil and filter change. All the fluids have been checked and topped off. It has four brand-new tires, and this truck is 100% ready to go. Oxford White is the color. We shoot all of our videos in 1080p, 60 frames per second. So if you have HD capabilities on your computer, tablet, smartphone, or television, I highly recommend turning them on right now, because it is your best way to check out the quality, condition, and options of the truck before seeing it in person. If you like the video and want to subscribe to our YouTube channel, where we do videos of our new and used inventory each and every day here at Summit Auto, in the upper right-hand part of the screen is a subscribe button. Click that, and then click the bell notifications, and you'll get updates every time we do videos here at Summit Auto. You can check those out whenever you like. We've got thousands of videos up on our YouTube channel. It comes with the steel rims. It has brand-new Advanta ATX 750 tires. These are LT24575R7 teams, and they are brand-new. They still have the little wear knobs on them. Frame and underbody. Just a little bit of dust on there, but for the most part, pretty corrosion-free. Front fender is in excellent condition. No dents or dings on there. Headlight lenses are nice and clear. Front bumper and lower valance are in excellent shape as well. I didn't see any dents or dings on there. You can get the painted front grille. The hood is in pretty nice shape. Maybe one tiny little ding on the hood, but other than that, pretty nice. Passenger side front fender looks really good as well. No dents or dings on there, and that passenger side rim looks really good too. As you go down this side of the truck, take note of how clean the body is, how reflective and mirror-like that paint is. We take these HD videos so if you are far away, or even if you're close by and just cannot make the trip down, but you're still interested in purchasing the truck, you can see the truck, hear the truck, and have confidence in the vehicle that you're looking at before you even get here. So when you do get here, there's no surprises, and you can make a smart and informed buying decision from wherever you're at. And if this video helps you make that buying decision, let your salesman know that you saw the video, and that Brett sent you. Back rim is in nice shape as well, and these back tires are brand new too. Framing on the body, really nice shape. Box rails all look really good. Like I said before, just a little bit of dust under here, but for the most part, pretty nice, and has all the remaining factory exhaust. Cab corners all look really good. Comes with the factory running boards. This is a one owner out of New Hampshire. Coming around to the back of the vehicle, rear bumper is in really nice shape. Full towing package, which includes the receiver, hitch four pin and seven pin wiring, no dents or dings on that rear bumper, and the tailgate's in pretty nice shape as well. Does have a locking tailgate. Lifts up really nice and easy. Bed's got a little bit of light duty usage, nothing a bed liner couldn't fix. It doesn't hurt the performance of the truck in any way. Going down driver's side, just as clean as that passenger's side, no dents or dings on the box. Looks really good, and for full disclosure, this back rim is in nice shape as well. You can see just how nice those wheel wells are. Didn't see any corrosion on them either. Coming down the rest of this side of the vehicle, doors look really good. They come with the telescopic tow mirrors. They have built-in directional signals. They're heated, they telescope out like so, and telescope in like that. And they are power. Inside the XL package gives you the grey vinyl interior, the 40-20-40 split bench seating in the front. No rips or tears on those seats. Does have lumbar, heavy duty rubber floors throughout on this truck. Tilt steering wheel, power windows, power locks, and power mirrors. We'll hop inside and check out the miles, the radio, and everything that this truck has to offer on the interior. See that this truck has 26,580 miles. You get a compass and outside temperature display. Instrument cluster is nice and clean. Information center controls and cruise controls on the left. Bluetooth and audio controls on the right. This one does have the six-speed automatic transmission with the optional tap shift.  It does have four upfitter switches. Climate controls right there. You get the sync system to connect to your Bluetooth cell phone, AUGS and USB jack, and a stability control that you can turn off. Pass in your side format. End seat are in excellent condition. No rips or tears on there. Smells very clean inside this truck. I don't think it's ever been smoked in. And the headliner is in really nice shape as well. Steering wheel is in nice condition as well. We'll take a quick look at the back seats, and then we'll start it up and take a look under the hood. Back seats are just as clean as front seats. No rips or tears back here. Has the fixed glass rear window. Does come with some sort of floor mat back here. I don't think it's for this truck, but it looks good. Keep your rubber floors clean. Has the child safety locks on the back doors and the bottoms of the doors all very nice and clean. Didn't see any corrosion down there. We'll start it up and take a quick look under the hood. Starts right up. No check engine lights or anything like that. Other than it's telling me my door's the charm. I would personally like to thank you for checking out the video today, and hopefully from this HD video, you'll be able to verify the quality and condition of this truck inside and out. Under the hood, we have the 6.2 liter V8 engine. Engine based very clean, runs very smooth. Once again, this truck has been fully safety. Has a fresh oil and filter change. All the fluids have been checked and topped off. Has four brand new tires. This truck's 100% ready to go. There's your emissions sticker. Really nice ride inside and out for a work truck F350. I'd highly recommend it from a quality and condition standpoint, and to see more pictures of this truck, or one of our other 450 new and used cars, trucks, SUVs, minivans, Wranglers, half tons, three-quarter tons, one tons. You name it, we've got to go to that website right there. www.summitauto.com Full pictures and descriptions of every single vehicle from two locations, all at www.summitauto.com. And if you'd like to check out more HD videos, you can go to www.youtube.com. Remember to like, subscribe, and share on this video and all the videos that you see there. Click those bell notifications. You'll get updates on the videos we do each and every day. Here at Summit Auto, in fact, in a second, you will see a link to subscribe to our YouTube channel in the upper left. Link to more F350 videos like this one in the upper right. Link to this vehicle on our website in the lower left. And a link to one of our latest YouTube videos in the lower right. Click those checks out. And we're super excited to help you with this Ultra Clean 2015 Ford F350 Crew Cab Short Box Single Reveal XL in Oxford White. Thank you all for checking out the video. Remember to like, subscribe, and share.


This mirror is about 70 centimetres in diameter and it's curved to a very particular shape within fractions of a wavelength and that allows it to form an image of the right place for our instruments. So a lot of the optical instrumentation work that we do here is from astronomy telescopes where we build instruments for the largest telescopes in the world, you know, 8, 10 metre telescopes and the next generation 25 up to 40 metres in diameter. So the glass in here is used as mirrors and it's not the kind of mirror that you have in your bathroom. We actually coat the first surface of the mirror. In this instance it's coated with silver. You can also use aluminium or gold. The glass that is used here is almost similar to what you might bake with at home. It's very similar properties and it's curved to a very particular shape within fractions of a wavelength and that allows it to form an image of the right place for our instruments. This telescope is going to be an optical ground station for laser communication research. That's where you use light and lasers from space to send information back to the ground. You can do that at very high speed and with great security. The value to everyone that's able to access what we have in space, you know, GPS, that goes straight to your phone. You've got earth observation data that look for flood and fire events, satellite imagery that people use all the time. So the value that ground stations like this provide is immense. So the particular glass that we use is really important because we need to match the thermal properties so it doesn't expand or contract too differently to the rest of the structure and so that it holds its shape. And it needs to be a material that you can polish so that you can get literally all the scratches out of it so that you have very good reflectivity from the surface of the mirror. Glass is definitely one of the things that makes all this technology possible. In order to achieve an optical system you need something that's transparent that you can shape very precisely and so glasses really fit that field very well.


Hello again. Well we hope you had a lively discussion and identified some key urban interface issues in your area. Now if you'll turn to page 7 in your student workbook, we can move on to our next topic, which is downhill and indirect line construction. You'll find a downhill line construction checklist on page 7 of your incident response pocket guide and on page 7 in your student workbook. Downhill and indirect line construction is inherently dangerous. No matter how hard we try to avoid it, we often seem to find ourselves in this situation. Let's hear what the field has to say on this. Constructing downhill line is something that we do a lot of as smoke jumpers and a lot of other people do it just because any time you get to it from the air you're going to be dropped off on top and sometimes even on an engine it'll come up on top. The things that you have to consider is number one, where are you going to start? Are you starting in green fuel cutting towards black? If so, you better sit back and you better think of a pretty good plan because that's not an anchor point and when the fire does if and when the fire does get up and go, it's going to get raced up to the top of the mountain and if you don't have real close safety zones, your escape route, it's a hard one because your escape route generally is always going to be uphill and you work and you work and you work and all of a sudden you look back up the hill and it's way up there and you know that you wouldn't make it if you had to. So things that I think about when I'm looking downhill at a piece of line that I need to construct is are there safety zones all the way down? Can I anchor in somewhere up here that I can make sure that it's not going to get around me? Rolling debris, you better have a look out every single time just for the fact of rolling debris or you can't see what's going on at the very bottom. You know that's happened in a lot of tragic fires, exactly that and you couldn't see what was going on and before it was too late you're too far down the hill and here come the fire. And like I said, always have those checks and balances and constant monitoring. You got to monitor, monitor, monitor. Don't say okay we've done it and then stay with that same plan. Things are going to change, fire is going to change, weather is going to change, you better adapt and change with it. If it starts getting to the point where you're not going to be able to do it, you get out and that's what I base my downhill line construction on as far as safety. I think one of my biggest concerns of downhill line construction is the fire behavior. What's the fire doing? Is the fire creeping around in light fuels that's going to provide a safe, you know, area for me to construct hand line directly against against the fire line of one foot in the black.  I believe downhill line construction is taken on an independent basis on the fire, the expected fire behavior, what the weather is doing. And you also have to do the risk to reward. You know, what's it going to accomplish if I dig fire line downhill?  Necessarily, you know, do I want to put my crew in that big of situation where myself is going to be headliable if something goes wrong? A whole bunch of factors play into that. You know, there's so many ways of doing it. You can dig line downhill and burn with your line. You know, as you go, you know, establish good lookouts no matter what, whatever you're doing, just so you can see what's going down there. And as a crew member or crew boss, I should say you should probably go down there, you know, leave your crew with another crew boss or squad boss, someone you feel safe with. Go down there and check on the situation yourself so you can see with your own two eyes what is going on down there or beside you or whatever. So, you know, something maybe isn't spotting over or hooking or something.  But it all goes down to a situation. If it's a dirty burn, you don't want to do it. You can decline. But it just depends on the situation. Those are some interesting comments. In this section, we're going to just throw you right in the middle of it with an exercise. On page 13, you'll find the details of your downhill, indirect, line construction exercise. Now let's go to Lamar who's going to help us set this up. Lamar? Yeah, Ted, this was a great fire. It was located on Elko District, Elko, Nevada. It was located. Time frame was around late August, really hot. I think the book actually does a great job of setting it up. And if you don't mind, we can go straight to tape. This fire was a result of a weather system that passed through the night before. It was burning sage, juniper, and moderate terrain. We arrived on the fire around 0900. We were met by the IC3 that informed us of the current situation and resources. The fire had been broken into two divisions. We were assigned to Division A along with two Nevada Department of Forestry crews and two Type 6 engines. There was a section of line between two roles that needed to be tied together. The problem with this division was that the fire was bagging over a ridge and at the bottom of that ridge was a drainage that led to a ranch and small community. On a positive note, there was an old road system that ran along the east side of the ridge and then turned west along the bottom of the ridge. This road tied into a well-used road that ran along the top west side of the ridge. It was decided that we would utilize this existing road by clearing it and burning out as we went along. The concern with this plan was that most of it would be downhill line construction with up canyon winds 10 to 15 mile per hour. We discussed this at length at our initial briefing. After tying into the road on top, but before we started our downhill assignment, we met with the strike team leader, safety officer, and we reassessed our situation and decided that three lookouts would be needed. The division suit would act as one lookout on the east side of the ridge. The safety officer would be on the top of the northwest side of the ridge and the assistance supervisor of the Jackson Hot Shots would be located on the top of the east side road. At around 1130 after re-securing the two roads at the northeast corner, we started working downhill on the east line. The winds were still up canyon out of the west. We were expecting help from the dozer that was walking in to support our operation. As we worked down the line, we brought a fire along with us. The Nevada Department of Forestry crews were spread out along the line and holding. At around 1300, the dozer showed up. It reinforced our line and took the lead. I stayed with the dozer the rest of the afternoon. The crew continued to burn out, secure, and patrol behind the dozer. At 1415, there was a spot fire across the line. All three lookouts reported at about the same time and the two Nevada Department of Forestry crews got right on it and caught it before it spread. The dozer backtracked to the spot fire to reinforce the line around it and then continued down the line. By 1530, the dozer had turned the corner and was heading up canyon. The crew continued to improve line and burn out, but held up for a while at point B until the dozer pushed past the head of the fire. Although the dozer was constructed an adequate line, the increased fire activity made holding this corner very difficult. Okay, remember your assignment is on page 13. At this point, you should work with your facilitator on Lamar's downhill indirect line construction exercise. Put yourself in Lamar's shoes and let's see how you do. Good luck.


Good morning everybody and it is also see how the interaction happens. So, we are going over to Hyderabad, there was a question. What is the difference between static pressure and total pressure? What is the difference between static pressure and total pressure? Sometimes I wonder we are teaching fluid mechanics or heat transfer. So, that is what professor Gaitande was saying we should have actually had first fluid mechanics rather than heat transfer. Anyway the question is what is static pressure and what is total pressure? What is static pressure? The name static itself suggests that something is static. So, this is what professor Anderson gives in his text book fluid mechanics text book not fluid mechanics aerodynamics. If I sit on a fluid particle and keep moving along with the fluid particle whatever pressure I feel that is static pressure, but while I am moving I am going to have the kinetic component also along with me that is dynamic pressure that is rho v squared by 2 that is dynamic component. If I add this static component of the pressure that is the static pressure and the dynamic component that is dynamic pressure then I am going to get the total pressure. So, this is static and dynamic pressure. Static pressure if you still are not convinced with my answer I had told on the other day itself how do we feel pressure? Feeling pressure is to go to its extreme end where there is no pressure. When do you do not have pressure in vacuum? You evacuate a chamber nothing is there. Why no pressure is there in the vacuum? Because there are no molecules. If there are molecules there is intermolecular collision because of the intermolecular collision there is pressure. So, I always feel the pressure as the collision of the molecules. When there is no molecule then there is no pressure because they cannot collide with anyone because there is no molecule. So, that is static pressure. Thermodynamic pressure whatever pressure Gaithundey has taught us is thermodynamic pressure that is this static pressure. There is no difference between thermodynamic pressure and static pressure. Thermodynamic pressure and static pressure are same only when we add the kinetic component to it that is the dynamic component to it that is rho v squared by 2 I get the total pressure to the static pressure. Is that ok? Thank you sir. Thank you. We will go over to NIT in Tiruchirapalli now. Sir, in the case of flow through the duct what is the correlation for nostril number, for laminar and turbulent flow, for entry length other than circular duct such as rectangular channel. Ok, good question. Actually in case of a duct in developing flow what is the correlation for friction factor and nostril number? Yes, we have not covered this in non-circular geometries. Why non-circular? Even circular we have not covered because this is a developing length usually we cover this portion in PG that is post graduate advanced heat transfer course. It is a good question, but we cannot there is analytical solution for that it is not that there is only experimental result. There are correlations available please put up this this is what is called as grades problem g r a e t z problem grades problem we have not covered this in our course please put up this question in the moodle we will come up with the answer for that. There are correlations as a function of x by d in fact if you if you want to see the correlation directly it will look something like this nostril number equal to some constant plus some constant upon r e into x by d. So and next is again constant upon r e squared into x by d whole squared. So the correlation is essentially a function of Reynolds number and the location where we are interested in getting the heat transfer coefficient. So we will put up this result definitely, but usually for a u g e transfer we do not teach this this is beyond the scope of the u g heat transfer definitely if you put up this question we will put up this answer in the moodle ok. We will now go over to St. Joseph College Kerala. In the case of flow over a flat plate is it possible that right from the leading edge the turbulent boundary layer starts? Yes good question for a flow over a flat plate we always study that initially there is laminar boundary layer then we have transitional boundary layer then we have turbulent boundary layer is it possible that can I get the boundary layer becoming turbulent right from the leading edge? Yes it is possible how can I do that that is how people do that is they put a tripping wire initially itself so that my boundary layer becomes turbulent or I can if I take a rough plate right from the beginning it is going to become turbulent that is when I say rough you imagine that sand grains have been poured on the rough plate and then immediately that provided that sand grain roughness thickness is greater than the laminar sub layer thickness which is what we have been insisting right from the beginning if you have broken that viscous sub layer because of the presence of the laminar because of the presence of the sand grains then definitely my boundary layer is going to become turbulent right from the leading edge. Thank you very much let us go over to J. N. T. Sir in a pool boiling curve the curve declines from C to D and then it increases from D to E so why is it so can you explain sir and one more question yeah yeah can you explain the Wilson plot in heat exchangers thank you. Wilson plot okay Wilson plot I have explained during yesterday's heat exchangers but still if you think that we need to answer that please put this in moodle I will answer that but essentially Wilson plot is used to measure the heat transfer coefficient on the tube side keeping the annulus side heat transfer coefficient very very high that is the essence of Wilson plot but I will answer that in greater detail through your moodle question but what was your question will you please repeat we could not follow that for now I am flashing the boiling curve with reference to boiling curve will you please ask your question. Climbing from C to D and increasing from D to E okay so why is it so can you explain. When C to D there is a decrease in the heat transfer coefficient and D to E why is it it is increasing okay so what is happening. Word of caution please look at the scale it is a logarithmic scale x axis is delta T which is increasing from about 100 at leading first point to about 1000 so heat transfer coefficient is not increasing what we are saying is that the the the wall temperature has increased suddenly and this transition region which we have shown so nicely by C to D line you cannot capture it so nicely you will in fact it is a region of oscillatory flow so you will have heat transfer very good at an instant very poor heat transfer when vapor is in contact at an extension so this line is just drawn for convenience in fact you will not be able to get such a nice curve at all okay so it is heat transfer is not heat transfer is not increasing or anything like that what we are saying is this part of the curve D to E has been obtained by this concept of this film boiling as you are making the film as the film is becoming thicker and thicker your heat transfer is going to become poorer and poorer okay but when the film becomes thicker the temperature of the gas or temperature of this vapor inside the film will also be higher so radiation heat transfer will become higher so that is a cause for heat transfer and increase there so it is not two phase anymore it will become single phase but radiation can contribute to even up to 60% of the heat transfer because of the high temperature okay remember for radiation it is to you all to the power of 4 so its contribution is very high okay thank you very much we will move over to PhD College Coimbatore which has to ask a question sir in turbulent sea measurements already told you animometer used to measure the turbulent sea in heating conditions in no heating conditions whether you use the animometer the question is for turbulence measurements we have always mentioned that we can use hot wire animometer but can I use hot wire animometer for heated conditions what all examples have given is all for unheated condition that is what you mean perhaps is that if I am having fluid flowing it is a cold fluid that is it is just maintained at ambient condition and we are doing the experiments under adiabatic conditions that is there is no heat transfer yes that's a good question under heated condition what will happen the fluid temperature is varying from one location to another location so it is yes it is difficult to measure under heated condition because the fluid temperature is varying from one location to another location why the basic principle over which this hot wire animometer is working is CTA that is constant temperature animometer it is called as why because the temperature of the wire is maintained constant that means what we are worried about is the temperature between temperature difference between the wire and the fluid but from location to location if the temperature difference between the wire and the fluid is varying then my calibration characteristics of the wire are going to vary why because my calibration I have done between wall temperature of let us say 400 degrees wire temperature of 400 degree Celsius and a fluid temperature of 30 degree Celsius if the fluid temperature is continuously varying my calibration characteristics are going to vary so if the fluid temperature is varying that is under heated condition it is difficult to use constant temperature animometer for that there are high high end techniques that is either particle image velocity symmetry or laser interferometry we have to employ is that okay okay so next question is conductivity based so conductivity varies from hardness material so we know do you have any relationship between the that's a hardness conductivity okay question is whether thermal hardness thermal conductivity varies with the hardness are you aware of any correlation for thermal conductivity with hardness honestly I don't know I never even thought that hardness would matter the thermal conductivity so far but you please put up this question we will try to see that and come back to you I don't know really let me think allowed why do you think that hardness would affect my thermal conductivity thermal conductivity is the arrangement of the molecules inside my body so why should hardness affect the thermal conductivity anyway you put this question let me answer by thinking or searching the material can I add something as a as a completely non thermal or unthermal expert wouldn't hardness also depend to a large extent on the arrangements of molecule anyway so in which case whatever arrangement of molecules you think is responsible for conductivity by implication at least the hardness should have some role to play because hardness and the molecular arrangement should somehow be related I do not know I'm just speculating would my friend from remote center like to comment on this observation and then I will ask him again to reflect back over to you okay sir so next next question is in heat transfer and thermodynamic subjects lots of assumption okay sir but in real and practical case not like that once a minute sir real and practical case is not like that so how can blue or how can what is the reliability of the subject see one thing is regarding your first question diamond and graphite are both carbon okay but I'm sure both of both of them have different hardness I don't know the numbers but diamond is used to cut metals so diamond is harder than graph graphite so there the structure is going to be different not that I'm an expert in all these things but thermal conductivity also is going to be different so if you go to from a point of view of lattice structure etc I think we will be able to understand this we can post it to our colleagues in metallurgy department and try to get some answers for it second thing related to assumptions I feel it is actually very philosophical okay see not being able to solve a problem is not an option so you have to solve a problem what is the accuracy with which you want to solve a problem that is what is going to drive our solution methodology now to have a solution methodology we need to have some tools and those tools are what we are getting to see from basic courses and even applied courses so that to that matter so what we teach in colleges though it has a lot of inherent assumptions it is actually developing the thought process more than the solution technique okay so the thought process how do I how do I put this problem in a mathematical form so that I can make it tractable otherwise no problem will have any solution okay so with that that is let me add on to this I don't definitely I don't agree that what all we are what all we have studied yesterday also I made this statement in the evening one of these students asked me this we I made a statement that what all we studied should we be throwing it to garbage because it is not not nearing to real life no I don't agree with you at all see my student had sat here and attended my PhD student sat here and attended at least for the convection portion because he was little jittery about convection the question for him is if I take a body and put it in a fire what is the what are the modes of the heat transfer important all this while you don't believe all this while we were considering radiation and convection what was I considering for convection I was considering forced convection when I when he saw this Grashof upon Reynolds number whole squared here and midnight day before yesterday we got a paper which was published by BRC Mysore which had taken natural convection so then we asked ourselves the question whether I should take the natural convection or forced convection yesterday evening we sat down and calculated gr by re squared to our horror we found that actually it is natural convection had I not known all these fundamentals about Grashof number Reynolds number and the velocity boundary layer thermal boundary layer and convective heat transfer I would not have designed in modeling how much amount of heat is received by my body because of fire so to identify which mode of heat transfer is dominant over the other I can only decide that if I am strong in fundamental if I am not strong in fundamentals I am not strong in applied research applied research feeds into fundamental research fundamental research feeds into applied research these two talk each other that is these two are complementary to each other they are not separate we are separating them because we cannot spend lifetime for applied research or fundamental research so applied research leads into fundamental research fundamental research leads into applied research okay so I will now go over to the K. K. Wag Institute Nasek My question is for the heat exchanger where counter flow is taking place and if you are changing the diameter of inner pipe so then how to analyze such heat transfer means what will be the effect on heat transfer then conventional piping pipe heat exchanger see what we are doing is what the question is in a counter flow heat exchanger tube in tube heat exchanger if I increase the diameter of the inner pipe what will be its influence of its performance first thing what is happening if I increase the diameter of the inner pipe what is happening the pressure drop of the inner side is decreasing number one if I assume that the mass flow rate is same what will happen to my Reynolds number 4 m dot divided by pi d mu my Reynolds number will come down if my Reynolds number will come down the Nasek number that is the heat transfer coefficient on the inner side will come down but let us see what happens in the outer side on the outer side what is happening imagining that your outer diameter is constant and I have increased the outer diameter of the inner pipe what is happening my flow area on the annulus has decreased so velocity has increased for the same mass flow rate Reynolds number has now increased because of which the heat transfer coefficient on the outer side will increase perhaps pressure drop will definitely decrease so pressure drop will increase so what is happening what is whatever positive thing was happening on the inner side now that has got shifted to the annular side so perhaps the effect will be more or less same but I will not conclude why because you will have to sit down and calculate this to get the exact feel of the numbers but by and large overall feel you get is that not much effect would be there on the area only one thing is if the if the circuit is thermally imbalanced if one side is very high heat transfer coefficient and the other was very low your overall heat transfer coefficient would be lower than the lower of the two so now if you have increased one of them and reduce the other the imbalance has gotten reduced so your overall heat transfer coefficient probably will increase a little bit and that would help in reduction of the area but that is again problem specific situation it cannot be generalized why don't you sit down and calculate this because it's not out of the world already one example is there just change the diameter put this in excel sheet and plot all the graphs you will get the area of the heat exchanger how it is varying so now you start thinking how are the parametrics affecting the performance of the heat exchange it may be a good idea to put a similar question in the test that is what we do often in IIT by the way some discussion takes place in the last lecture of the course and two days later in the end same you will find a large 10 mark question only on that particular discussion and those who did not attend the last lecture would suffer horrible there is a government college Salem let's go over to government college Salem sir in studying radiation through electromagnetic waves so whether what type of wave motion we can able to study about it whether longitudinal or axisymmetric or flexural torsional whether something can be connected to that see you the waves general question is the electromagnetic waves which are studying in radiation are they longitudinal or various other cases you have taken let me cut short that question let me say that generally these waves are transverse wave generally these waves are transverse okay that would be the answer shortest possible answer I can think of but whatever I taught yesterday was all through modest there is a initial discussion in thermal radiative heat transfer radiative heat transfer by modest about this longitudinality and the transverseness itself initially people were thinking that these waves are longitudinal but later on they realize that they are transverse okay okay sir one more question sir okay as thermal thermal radiation is being discussed throughout sir whether can you just flash some points about atomic or nuclear radiation question is you have only focused on thermal radiation you are not focused on nuclear radiation professor first thing I don't know what is nuclear radiation okay so that is not the answer the answer is what are we looking at the thermal aspects this course is all about heat transfer so that's why we said always when I used radiation I use the term thermal radiation the qualitative sorry the objective what I need to use for radiation is thermal radiation definitely we are not covering nuclear radiation at all because nuclear nuclear radiation doesn't come under the purview of thermal radiation that's what I emphasized when we studied Planck's distribution the Planck's distribution is all about thermal radiation by virtue of temperature whatever radiation is taking place is thermal radiation nuclear radiation that is x-rays and gamma rays are not under our purview okay I have a question again as a mutant observer not associated with this I would submit that whenever there is a nuclear radiation there has to be an accompanying thermal radiation because of nuclear radiation so it may perhaps not be completely correct to say that nuclear radiation is outside our purview but perhaps the right thing would be to say that while nuclear radiation itself may not be in our purview any thermal radiation resulting out of nuclear radiation is certainly of concern this is a good point or what Prasafatek has told in fact always we said no we cannot actually differentiate things we need to take them in an integral sense yes actually that's what in nuclear replication this is called as Neutronics and Thermal Hydraulic Aspects Neutronics and Thermal Hydraulic Aspects cannot be separated actually they have to take they have to be taken together in fact what was happening in Fukushima Fukushima what was happening neutron activity was going up what was they trying to do they were trying to take the water from the sea and pump in water into the Fukushima nuclear reactor containment what was happening it is actually both neutron activity and the thermal hydraulics neutron because of neutron activity there is increase in the temperature someone has to take out that heat transfer that high temperature who is trying to take it out the water the least possible thing one can do is to pour water actually I need to spray water but I cannot do because it is an emergency I have to just take water from the ship and pour it because I don't have motors and pumps because there is no electricity there I am just using my ship which is sitting far away and pouring water on how effective it was only time will tell because we don't know people are indeed sitting and studying the thermal hydraulic and the neutronic aspects they feed into each other that we cannot separate them out professor is right but we are not taught you neutronics that's all I want to thank you very much there is a question from SVNIT this would be the last question that we would take over to you SVNIT I am always wondering about the term that NTU number of transfer unit so can you please elaborate this term NTU because as you see the NTU definition it includes overall resistance surface area and semen so if we eliminate the fluid properties and the wall thickness the only term which is representing the NTU is the surface area so this term was introduced because of the number of heat transfer units will be incorporated to increase the heat transfer okay the question is what is to put it short what is the physical significance of NTU him and just one clarifications NTU is a name given to something which refers to the dimension size so okay number of transfer units probably the name is what is bothering it just refers to the surface area associated with heat transfer so whether you call it number of transfer units or area term it doesn't matter now you said that you take away the conduction etc what is NT what is that NTU what is that we are looking in fact why did we get to NTU let me ask him and you always wonder I know but what is that we are doing for NTU why did we introduce NTU why did we introduce NTU NTU because we wanted to get the relations for the heat transfer load in terms of area remember in NTU method unlike in LMTD approach we know the area in LMTD approach we didn't know the area we had to figure out the heat exchanger area but in NTU method we know the area that's why the area is there in NTU so having known the area what would be my heat exchanger performance if I have to quantify that that has to be done in terms of the known parameter which is NTU that is area NTU for all practical purposes we can think that as area that is why we say if NTU is large size of my heat exchanger is large if NTU is less size of the heat exchanger is less provided as you rightly said U that is the resistance is same and m dot cp that is the mass flow rate into specific heat of the fluid is same ok. In fact that is why see you have a given heat exchanger of a given dimension you are calculating the performance how good it is and suppose you decrease the length by half in fact in that convection 5 the slides it was told double the length you could get almost 99 percent of performance. So, what we are trying to say is this increase in the surface area does not translate to a corresponding similar increase in the performance. So, performance evaluation is possible because of this non-dimensional term called NTU which is nothing but a representative area I would call it you probably usefulness of this exchanger or something may be that is what it is. Sorry in addition to my question is it based on experimental or pure proposed theory? NTU is it obtained experimentally or see NTU is not coming out experimentally what is that we are looking for we are writing an equation for effectiveness. Effectiveness is a function of NTU and ratio of the specific heat why ratio of the specific heat that decides my temperature gradient and NTU decides my area. So, professor Arun has been insisting whether it is heat exchangers or fins or constant wall temperature constant heat flux boundary condition in case of convection all the time the driving force the driving potential in heat transfer is the temperature difference. So, the effectiveness is a function of NTU and ratio of the specific heat how did we get this we have derived this from fundamental and these derived things have been found over experience, but that they are going to be near nearer to the experimental results they are not very much of within the experimental uncertainty is that ok Hemant. Yeah, yes sir. Thank you very good thank you thank you so much.


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It looked like judges final at bat might have been in that seventh inning But your team continued to pass the baton pass the ton and score runs there in that eighth Can you just describe what it was like as you were watching them continue to punish pirate pitching? Yeah, I mean good to have those kind of the bats and and pour on you never want to take anything for granted You know everything affects different things so to have them continue to grind away at bats Glaber getting us started with a with a homer and then finishing off there with a big homer was was great, but You know I thought a lot of good at bats all night put us in position to get some big hits and obviously cabrera Getting it started following some of bats where they really made contrarre's work. You know contrarre's good-looking young pitcher and you know after that homer he kind of settled in and was pretty tough on us, but Yeah, good to see everyone just Making it difficult, you know, even when you don't get a hit or don't get a result And that ended up work really working out for us in the end you mentioned cabrera What have you thought of him overall in left field and just his contributions since coming up? It seems like he constantly finds ways to just provide a spark just that he really has you know He's he's done it a little bit different.  I mean Let's not lose sight of the fact that this is a really talented infielder. That's that's playing in the corner right now in the outfield and Really just handling it with a with a maturity and a confidence that's That's been great to see Could you feel the added energy in the park throughout the night and I could it was it felt Yeah, you know even even more so to me than last night, you know, he used to kind of get locked in but tonight it felt like you know Waiting for that big moment obviously and it did feel a little bit different tonight


The 2022 has been an amazing year so far for new golf product, but in my opinion, one brand has absolutely smashed it. You see, the thing is, there's been some amazing product, like I said. Callaway release, well, their new driver range has been incredible, as was the Road Pro Irons. The Zuno Iron Range, again, fantastic. The Ping Glide 4 wedges were released just a month or so ago, and they were also incredible. And let's not forget Cobra's new driver line, which yet again has performed incredibly well. None of those brands have managed to achieve what this one brand has done for 2022. As well, you see, the thing is, every year there will be a standout product that everybody has. One brand has a standout product, but never does one brand have every single product in the range that I would stick at possibly the top of the tree. Like I said in the intro, from ball through to driver, one brand has got everything right this year. And that's a real shock to me. And amongst all that, there's a real surprise package as well, which I'll reveal very, very shortly. No introduction, and that smack bang in the middle of the fairway. You've seen it on the previous clip, so there's no clues really that I've given away that, so don't tell you that this is all about tailor-made. But don't go anywhere, because there's been a lot of noise made about this stealth driver. But to me, there are many more stars in the show of this range this year. I'm going to tell you exactly why you shouldn't be overlooking tailor-made in 2022. We're kicking on the top side of it, but next up is fairway woods. Now for me, I want a couple of things from a fairway wood.  And with these woods, they do that extremely well. And for me, the thing that it does really well is it launches the ball incredibly high. It picks it up really good. We're getting some ball speed off the bottom of the cup face, which is again, is really, really important for average golfers. So whichever you're looking for, from three through to five wood, I think there might be a seven wood in the range as well. Then these do these woods incredibly well. And they look fantastic as well. So great ball speeds, great launch angles, make them very playable for average golfers. They're in the bag. What's up next? Right, so with this stage of the video, I want your feedback. If you were choosing to play one brand right now, what would it be? Because there's a lot of brand loyalty out there. Often that's kind of misplaced in my opinion. You're not necessarily picking the best product throughout the bag. It is just all about brand loyalty. But if you had to pick one brand right now, which one would it be? Well, more than happy with where that one has finished up. But more importantly, what matters to you is this. I've tested the three, four and the five hybrid out of this range. Don't forget, there's two head types for you to choose from, depending on what you're looking for. What I find particularly good about the stealth hybrids this year was two things. Ball speeds, incredibly fast off the face and good carry distances, therefore, and also the ability to launch the ball extremely high. Now, I think two of those things are really key in finding the right hybrid that suits you. But don't forget that broad spectrum as well, right away from three, I think maybe even into seven hybrids is available as an option. And again, a massive box tick from tailor made. So what's next? So, so far, I've told you about the stealth driver, which you knew a lot about the fairway woods, the hybrids, which you probably knew a lot about. It's one product yet to be revealed, which I think is possibly the star of the show and caps off the whole lot for tailor made. And I'll reveal that shortly, so don't go anywhere. So we're into irons and I'm not going to hit every iron on the camera, but when you consider what's out there right now from tailor made, we've got the stealth irons that's pretty much the game improvement iron. You're then looking at P790s, which is their left foam injected players distance iron that category would be P770s, a finer, more refined offering of the P790. Three incredibly good irons on offering their 2022 range. And then if I tell you that I think in October of this year, we're due the new iteration of the P series. Then yet again, there's an incredible range of opportunity for average golfers to choose an iron that suits their game. And each and every one of them is incredibly good from tailor made. So as I said at the beginning of this video, we're going to drive it through to iron so far. The choice is incredible. And I'd argue that it'd be hard to pick fault with any product that I've shown you so far. So that bottom end of the bag putters the spider GT range. Well, in my opinion, they don't come any better in terms of the quality of the build. Again, each offer the face inserted superb in terms of the way it feels. There's a number of different models to suit each and every eye in terms of what you want as an individual. But yet again, you can't criticize the way in which spider GT range has been put together. Very much like the same as everything now that we've seen so far from driver right the way down to putter with one item left. Okay, so we've returned inside and apology for the audio earlier on the video. I still quite late on that there was an issue. So apologies for that. I've returned inside the van and I will reveal what I think is well, possibly the most interesting release from in 2022 from this tailor made range. And it is an odd one. But before we get there, let's not forget to mention the MG three wedges from tailor made, which again are superb quality performed exceptionally well. So like I said, all through the bag, unreal in terms of my opinion on how good these products are. But then this special product, what is it? Well, it's a golf ball and it's a golf ball very much with a difference. But first of all, it's a tall response ball which performs incredibly well again for many, many average golfers. And it's had a good price point for the quality of ball that you're getting. But then the alignment aid, the visual alignment aid they've included in this ball is significantly different than what I've seen before. Now I know we've seen triple track and we've seen a few other balls that have sort of led the way, I think to be fair, in this kind of marketplace. But I think what tailor made have done is created something that is really visually very, very strong indeed. It also is incredibly easy to align. And when you couple that with a ball market, if I can get that ball to rest there for a second, the ball market is incredibly good as well. And like I said, let's not get too carried away. It's a ball market. But this coupled with the ball is a superb way of aligning things. And I think that's incredibly, first of all, it's easy. It's a lot quicker than just aligning the lines on your ball, the markings on your ball. So to put this in position, first of all, place the ball in line with the market. It's so, so good. Trust me, it is so effective in terms of getting your alignment right. I just cannot believe that in the next year or so, we don't see a putter with the same colorings on that match this whole thing up together. So ball marker and your putter head is going to have this kind of visual look on it in my opinion. But trust me, like I said, first of all, an exceptionally good golf ball, but the alignment aid is just so, so good. It's so strong in terms of its visibility. They just took it to another level in my opinion. And like I said, really just cap off what is an incredible range from TaylorMade. My summary is going to be a very, very quick one. I put this video together simply because I was testing TaylorMade product and I just kind of thought, you know what, that's, that's decent. Then I picked up another product with the TaylorMade range. I thought, well, that's decent. And obviously so on and so forth until right away through the range. I thought, well, has anybody actually produced a range that I have felt that is as good as this right the way from the ball that I've just shown you? Right the way up to the top end of the bagging driver. Like I said, some people are brand loyal. They don't like TaylorMade. They do like TaylorMade, whatever. I think if you put everything to one side and just ask yourself the question within what I've shown you today and we've got the P Series coming later on this year. I think TaylorMade have put a real good product range together. And like I said earlier, I'd find it very hard to criticize what they've put out right now. On every level, from a looks perspective, from the kind of feeling sound, from the performance levels, everything is ticking the boxes that you should be looking for from an average golfer. So my message would be a simple one. If you're considering buying new product this year, then I reckon you should be considering putting TaylorMade into your list of possibilities to try. That's all I've got to say. Right, I'm done. I'm trying to hold on to my little muckly down here. A little penny is making an appearance there. She's just on that other camera. You can just see a little bit of her. So she's getting a little bit bored of me waffling on and no doubt you are too. So we'll call it a day at that bit. Thanks for watching. As ever, feedback down below. Love to hear from you and hit that like, thumbs up button. Get involved in the channel in whichever way you can. Thanks for watching. I'll see you all soon.


So, evaluation VR systems. So, in other words how do we know whether you are making progress right you you made one experience ah I have improved it I have made something better are you sure right. So, how do we know um remember that um when we talked about um we talked about neurobiology in the very beginning lecture and perceptual psychology as well um we have ah where VR was applied in a lab to study how organisms are affected by that we talked about um VR applied to ah insects such as a cockroach we talked about it applied to rodents as well. So, imagine applying it to a mouse um all the way up to perceptual psychology which corresponds to applying virtual reality to humans right. So, when we do that there is very clear separation of the scientist and the laboratory subject. However, if you are an engineer or developer of virtual reality systems that in this case you may commonly be moving back and forth between these two without even being very much aware of it right. So, just be aware of it every time you try your experience you become the laboratory subject and then you go back and try to be the scientist again right um and it becomes even worse because you know the scientist might at least at least in principle it is supposed to be dispassionately trying to determine whether some hypothesis is true or false. So, they really would just like to know what is the truth. The developer would like to be done with their task have everything work well and either it is part of a business or a class project whatever the case may be or just making a good experience um. So, they have a vested interest in having the hypothesis come out. So, that they have made something good right. So, um so that is another kind of problem. So, they are already even as a scientist if they were they are quite a bit biased um for the outcome to be in their favor right alright. So, what options do you have I will mention two options one ah train yourself to be a critic I will say a good critic or maybe a bad critic in the sense of train yourself to be very negative and hostile towards your own designs difficult to do maybe um two design an experiment and recruit test subjects right. So, recruit people to try it which one should you choose I suggest choosing both of them right. So, obviously, the first one is the the laziest one right. So, um train yourself and then you can evaluate what you are doing with very quick frequency and without doing a lot of extra work. Number two may require a significant amount of extra effort and work and. So, you end up doing this depending on how much um your life depends on it right. So, so what exactly you are doing are you building an entire company around this you better do a lot of experimentation and testing are you building your entire career basing it on this then do a lot of testing. If it is just something for fun to share with your classmates then fine let a few of your classmates try it and um and get some feedback right and that may be enough to make you happy. So, choose both let me give some advice under these two cases. So, what if we choose number one? So, for yourself let me give some key points one thing is recognize your own bias recognize your own bias. So, one of the things I will say about that is um you are going to know more about what you are trying to do what is the intention of your experience than anybody else right. So, if you know what you are trying to do it may be the case that you have some kind of motion occurring and you know that the object is moving not you, but if someone tries it and they do not know either way they may think that they are the one that is moving and then they get sick and then you complain why are you getting sick and then and then um and then you say well um you know it look like I was moving and then you and then the creator might say well well duh of course, you are not moving the object was moving did you get it you know. So, um so, it will actually affect the outcome of sickness here in the simulator sickness based on what interpretation your brain is giving. So, you have to be very careful about that um the other thing which I already mentioned is you might be very proud of what you have made or lazy right.  So, that is your bias right you you are either proud or lazy you do not want to redo it or you are happy of what you have made you are biased by that and um only you understand what it is supposed to do. What else um adaptation this is from perceptual psychology. So, you might perceptually adapt. So, you may have made some bad choices there may be some errors in your system you have learned to adapt to those they do not bother you anymore. Maybe you have made something that is horrible from a from a vestibular mismatch perspective, but you have made so many horrible experiences before that they do not bother you anymore right. So, you you adapt to it um the more experience you have in general with virtual reality the harder it may become to um to detect the flaws. So, you may need fresh subjects. One way to fight against that of against the adaptation is to put yourself through what I would call perceptual training. It is like training a detective to look for clues at a crime scene right look for the clues try to try to find the things that you would ordinarily miss and look for them and then as you develop experiences make sure you are finding them again. So, try to um try to see the flaws that maybe were invisible before. I am going to give some examples of this that I myself experienced. So, one observing latency. So, tracking and display latency ok. So, suppose you have some head tracking and maybe something has gotten messed up right. So, so it is hard to tell you would like to verify that um here is what I like to do. I like to look at a vertical line about 2 meters away in VR. So, it is comfortable it may be a door frame or or side of a window and then I go like this. So, I move my head back and forth at about 2 hertz. If I shake too much at a higher speed then the headset might start to move with respect to my head and I do not want to do that. If I move too slowly then I might not perceive latency anymore. So, I picked a kind of intermediate speed about like this. If I move at too far of an angle then I might also have problems because of optical distortions things like that. So, if I just move like this small angle at about 2 hertz then um I can adjust with some keys let us say the amount of prediction that is going on in the tracking to try to compensate. Ideally it should all be working fine maybe there should be effectively no um latency, but you can then move the keys and you can show yourself what does it look like when there is a 40 milliseconds of latency 100 milliseconds of latency. What does it look like if I overshoot I try to predict and end up arriving the images end up arriving 50 milliseconds ahead of where they should be right. So, you train yourself to look for that and then um try to zero in and get it to match as closely as possible as it does to the real world and again you can go to the real world and look back and forth at something try to match it you are using the vestibular ocular reflex then do it in VR and see if it looks right. Um when I started working um on VR in 2012 I could only see latency down to about 40 milliseconds when I first started playing with these systems. After about a year and a half and and perceptually training myself I could detect latency down to about 2 milliseconds. So, so I think that is very close to the limits of human perception that is very important. So, all of a sudden I have trained myself to be a verifier of whether or not the latency has been handled correctly. So, you should do that rather than training yourself to just adapt to the latency and have your brain convinced that that is fine right and then you may have some discomfort or or um um maybe fatigue or maybe simulator sickness at the end because you have not trained yourself to look for it. Um another one um observing optical distortion. Remember that we have lens aberrations with a high field of view lens. So, what you need to do to see optical distortions in any kind of problems with those is you have to be looking through the sides of the lenses. Now, you could just go like this move your eyes to the side try to look around, but why not use your vestibular ocular reflex. So, what you do is you look at an object in VR you fixate on it and then move your head back and forth a lot. And in fact, better than picking an object go to a place where there is a lot of rectilinear structure where there are vertical and horizontal lines maybe in a nice room as I look around on this classroom look at the blackboard I see um I see lots of um structure vertical and horizontal lines. So, do that and then move your head back and forth so that you are looking out of the sides of the lenses. If there are optical distortion issues you will see a significant amount of warping or swaying in these vertical lines. So, so look for that. If you go do that try that in the lab you will find that even if you compensate for it in software you still cannot compensate for all of it because your pupils when you use your vestibular ocular reflex like this are translating away from the center of the lenses. So, you are moving across different parts of the lenses. Um another one observing stereo mismatch. So, I am supposed to be showing perfect stereo rendering for the right and left eyes um what if I got it wrong. So, what if for example, I I have I have everything match perfectly except I have decided to draw a butterfly, but the butterfly only shows up for the left eye. You think you would notice?  So, the way to do it how would you do it? Well, close your right eye and look through the left and then close the left eye and look through the right and see if you get different pictures very simple, but people usually do not do that right. So, that is so that is one one thing you can do close close one eye and then close the other and compare the images that you get right. So, very simple. So, there are many many procedures like this you may need to be clever about them as you suspect different kinds of flaws in your system. Questions about that? Alright. So, now that is for yourself. What about um designing an experiment? Now, there are plenty of books and courses just entirely on this and we have to design experiments when there is human perception involved. So, if that is the case um I highly recommend you read about and use methodology from perceptual psychology. You should believe this from the things we have talked about in this in these lectures for this course especially the area of psychophysics. Let me just give some highlights you definitely need to have a clear hypothesis right be very very clear about what it is you are trying to establish not just always my system pretty good you know I just try to come up with very very clear um hypothesis about what what you are trying to reason about you have two methods of locomotion for example, method A method B which one is more comfortable from a simulator sickness perspective which one is is um more effective in terms of um way finding you know are you actually building a kind of map of the environment while you navigate around or not or as it become too confusing and disorienting. So, formulate the hypothesis very clearly um do you need um a few subjects or many maybe hundreds of subjects? You do not always need a lot of subjects for some experiments in psychophysics it may be just that three or four subjects is enough. It may be based on a simple phenomenon maybe the response time of your vestibular ocular reflex and you do not need to have hundreds of subjects to determine that it may be um very very similar very very close range of a small amount of variation let us say from human to human you just need to measure it. So, you need a few humans to make sure that you have gotten the measure accurately you have done things correctly um. So, perhaps you just enough to um to to believe the data um and not be overwhelmed by one or two outliers right um versus some kinds of phenomena especially when we talk about simulator sickness you may need to study it over a very large number of people um related to this is our demographics important who is going to be using your experience and does it matter you know men and women may have different um um different experiences and maybe different results based on gender maybe different results based on age maybe different results based on the amount of experience in terms of sitting in front of giant displays right. So, so um if you have a group of people who have been playing first person shooter games for the last five years very regularly they may have a different response to the kind of stimuli that cause simulator sickness they may be quite immune to it in a lot of cases um can you take automatic measurements can you take automatic measurements or do you have to ask them how they feel right did you like that experience did it make you sick maybe you can measure the galvanic skin response which has to do with the conductivity across their skin which I measure whether or not they are sweating which may then give an indication of whether or not they are starting to get sick. So, there are different things you could measure or at least it may have some measurement of their emotion while they while they use the system there are also other measurements you may be able to take that may give um um indication of um of simulator sickness maybe how they move their head how their balancing is affected um you may be able to measure that if you do not have to tell them to give you a response in some kind of questionnaire you might have an advantage if the automatic measurements um can directly correlate with the the hypothesis that you are trying to resolve. So, automatic measurements or do you have to ask them questions you have to make a questionnaire um do they know what you are trying to measure which do you think is better should they know the hypothesis no way right whatever they know about they may be trying to help you right or they may be the kind of evil subject they may try to harm your experiment right they may say ah I know what they are trying to measure I am going to keep answering the opposite you know so um so it is best that they do not know um part of that is you should provide this is very common in psychophysics and perceptual psychology provide a stimuli in random order like for example, when we talked about perception of equal loudness do you want to start off soft and just gradually increasing it may be better to just present them with sounds at random levels and then have them indicate whether it was um louder or softer right if if you are trying to determine that um could maybe ask them if it is equivalent, but then I guess there is the difficulty of how much time has gone by since they have heard the base stimulus. So, um so if you have the opportunity it is better to present the stimuli in the experiment in some kind of random order without them having any idea of what you are trying to measure um another one is um adaptation adaptation is that an issue or fatigue right. So, it may be the case that as they are doing the experiment they adapt or maybe you have had the same subjects coming back day after day well you might need some fresh subjects or maybe they become fatigued right if they become fatigued then they will have different responses near the latter part of your experiment good thing use random order at least right if you if you save the best for last you know then um then that ordering and their increase of fatigue will affect the outcome. So, these give you some general ideas of um the kinds of things to pay attention to in designing your experiments it is not at all easy and it is especially difficult for engineers, but there are people who have studied this they do this all the time um they write books on it you can get advice you can talk to perceptual psychologists at your university um and um and get um ideas on what you should be doing here. My questions about this all right have one one final reference that I think is very helpful for general research scientific questions whether it is engineering or um perceptual psychology aspects and it is the handbook virtual environments um make sure you get the second edition which is from this year 2015 it is an edited series by Hale and Stanny um it is a very thick book an enormous collection of of survey papers that survey many many different aspects of virtual reality or virtual environments. So, um so I find it an excellent source for all of the current up to date scientific literature at least up to probably 2014 and then the and then the book was made, but this is a great source you can find many references in there and then search for references that reference those references that are that are newer after that and you can find a huge access to the the literature on that um. So, that is all for the course let me just remind you of what we went through we started off I start off giving you a definition of virtual reality that um emphasize that its engineering plus some organism that is being subjected to artificial stimuli. So, remember that the organism is a key part of that. So, and in the case of um most of what we talked about in the class um you are the organism that is participating in it. So, make sure that um you take that into account and whatever you evaluate. I gave you a bird's eye view where we talked about the hardware the software and the software mainly involved in alternate world generator which today are mainly um its most popular to use game engines, but who knows what the next generation is going to produce. There should be virtual reality engines that make it very easy for developers to develop experiences. Game engines are not ideally suited for that right now, but they're trying to adapt them and I gave an overview of perceptual psychology. Then we went into geometric transforms and models right. So, how to model these um alternate worlds and transform them so that the right information appears on the screen. Then we talked about light and optics. We got into the physics of it and then once you understood optics and light we talked about lenses and then optical systems that are engineered to make for example, a head mounted display, but then we got into the human eye as an optical system. And then we went into the physiology of the human eye. We went into photoreceptors which are like the input pixels. We talked about the optical system of putting a display in front of your face and going from pixels to photoreceptors. And then we went into human perception and physiology. We went from photoreceptors to um talking about the retina, the neural structure that's part of the um the eye which goes from the um the photoreceptors to the ganglion cells. The information is communicated along the optic nerve arriving into the visual cortex. So, then we got up to the levels of perception. We talked about hierarchical processing of the brain and the whole visual system. And then we had perception of um motion, right? Um part of that is is complicated by the fact that our eyes move. So, we covered um the motion of our eyes. We covered perception of motion. We covered perception of depth. And I emphasize that there are many other kinds of perception like perception of scale, perception of color. So, now that you understand that template you can study other aspects of perception. Um we then described systems of tracking because we have to track the motion of um the human head and perhaps more of the human body in order to make a perfect kind of correspondence between the physical world and the virtual world. Then we got into rendering for for the visual case. Much of that was standard computer graphics kinds of concepts, but there are many particular aspects to be concerned with when we get to virtual reality. For example, aliasing becomes much worse because of the changing viewpoint that we have and because of the stereo perspective that we have. Um so this becomes a serious and difficult issue. Then we talked about audio for virtual reality and we covered many of the same kinds of concepts that we did for visual. Um there are rendering issues. There's human physiology issues. There are perception issues. We covered these for audio. We could have done the same for haptics and touch or for um for smell and taste. Whatever other senses you want to bring into the virtual world. We talked about we could talk about these as well in the same kind of style. Um the vestibular organ was also mentioned because it's very important, especially in the case of vestibular mismatch. It also is what helps power the vestibular ocular reflex, which is very important. And then finally we ended by getting into uh interfaces. Some of these higher level aspects going across locomotion manipulation system control and social interaction. And then I concluded by giving you um an overview of how to evaluate VR systems, whether it's yourself, especially emphasizing perceptual training and then the design of experiments involving human subjects. And that brings us to the end. Thank you very much.