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Visual Studio Subscriptions
Today’s Visual Studio Toolbox, Aaron and Katie are going to show us the great resources available through Visual Studio Subscriptions. [MUSIC] >> Hi, welcome to Visual Studio Toolbox. I’m your host, Robert Green, and joining me today are Aaron Mask and Katie Bushland. Hey guys. >> Hey, thanks for having us. >> Hey, there. >> Welcome to the show. You guys are Program Managers in Visual Studio land, and you’re joining us today to talk about Visual Studio Subscriptions, which I think are an under appreciated and underutilized resource, as we’re going see if a lot of people watching probably have one, and there’s great resources in there, but if people don’t know what they have and what’s in there, then they can’t really make use of it.
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COVID-19 LulzBot User Community Response.
LulzBot 3D printers are on the front line in the fight against COVID-19, As LulzBot users across the country have teamed up to produce critical equipment for hospitals and healthcare workers. And LulzBot is committed to joining the cause by providing filament for virus fighters everywhere using their energy technical skills and 3D printers to help contribute to the battle against COVID-19. With profiles for over 30 different filament types LulzBot 3D printers offer the versatility and reliability to meet today’s challenges.
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How one archaeologist is preserving Egypt’s cultural heritage
My name is Dr. Monica Hanna I am a mother, archaeologist and a scholar, and I use Google to help preserve Egypt’s heritage. Egyptians are interested in their past, but research about Egyptian heritage has mainly been done in the west. 95 percent of students have never been to a temple before. And if we do not connect the people of the present with their past this past will not live.
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IPad Pro Magic Keyboard | Review
I’ve used my ipad pretty much every single day since the day that i bought it i absolutely love it it’s light it’s lightning fast and does everything that i need it to now i use the ipad primarily as a note-taking device in this position here using notability to take notes in my medical school lectures i’ve wanted a keyboard for the longest time i wanted one so bad but there was never anything good enough on the market and so i waited and so today that way is finally over things we don’t need so this is it this is the new apple magic keyboard so in today’s video i’m going to show you and demonstrate to you everything you need to know about the apple magic keyboard so that you can decide if you want to purchase one for yourself the first thing that i want to comment on is this magnetic snapping into place it is very sturdy i wouldn’t be worried about my ipad falling out or anything even with a lot of shaking the second thing that i noticed is that this is decently heavy it’s not quite as light as the ipad by itself or the ipad in the smart folio case that i had before in fact the case feels almost as heavy as the ipad itself i’d say the ipad is still a little bit heavier in weight but i’d say they’re pretty close and just for comparison i’ve got my 13 inch macbook pro over here and comparing the two the macbook pro is definitely heavier but not by much they’re fairly similar if i’m honest as far as the thickness of the ipad with this new keyboard in case anyone is wondering now the keyboard itself has two hinges on it there’s the main one down at the bottom over here which also has a convenient usbc pass-through in order to charge the device while it’s in the keyboard case and then at the top there’s a second hinge which allows you to change the ipad to different viewing angles now let’s move on to talking about every aspect of this thing all right let’s start by talking about the keyboard so i’m going to open up my note-taking app of choice notability wow it feels so strange using a keyboard and trackpad on my ipad alright i’m going to select the textbox tool and start writing hi my name is nasser and i’m studying for the usmle exam okay right off the bat that feels very very good definitely better than this keyboard that i’ve been using for the last year and a half or so in comparison to that keyboard the travel of the keys is a lot deeper they feel almost more mushy like they’re a bit softer and have more padding these keys over here are a lot more hard and clicky the keyboard is of a normal size so i don’t feel like my hands are cramped close together or anything like that in fact i think they’re about the same distribution as this one over here yeah it’s the exact same size as my normal keyboard all right after having typed over there for a little bit i can confirm that my fingers don’t hit the ipad when i’m typing and if my fingers don’t hit the ipad well then yours probably won’t either i also want to make the comment that the keyboard itself is not flimsy at all i’ve also noticed that the keyboard is actually quieter than the other one which i’ve been using i’ll let you guys decide for yourself alright and now the same sentence typed on my old keyboard all right now let’s move on to talk about the comfort of this keyboard case on the ipad in different situations so sitting down at a desk like this i can definitely say that the viewing angles are more than enough even for someone like me who’s quite tall and might need the ipad tilted back as far as it possibly goes which is something that i cannot say about the previous keyboard for the ipad those viewing angles were always a bit too shallow something like this and they never provided me with enough of a tilt to feel comfortable when sitting down and typing now as far as sitting down on a chair goes maybe you’re a student in a large lecture hall and you don’t have anywhere to set your ipad down i personally own the 12.
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JSON Concepts To Remember 😌
hey YouTube this is Prince from Desi programmer and welcome back to another exciting video and in this video we are going to talk about JSON also I took our almost everything about Jason in this single video and to get the most out of this video although you don’t need to be a pro Gorder but still you should have some programming experience I’m actually planning to roll out a couple of videos about web api’s even in node GS and infra so I thought it would be better to first give an insight about G Sean now talking about Jay Sean which stands for JavaScript object notation it is a lightweight data interchange format which is easy for us that is humans to read and write and also is easy for machines to parse and generate jason has almost replaced XML from the market and there are other alternatives from Jason - like ml Jason ain’t a programming language first of all it’s just a text storing form it you can use JSON for almost all the modern web api you can see it being used in almost all of them and also it’s used widely for destroying configuration data such as our vs code settings itself now in this video I’m going to use node.
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Making sense of the 3D linear momentum balance equation (Fluid Dynamics with Olivier Cleynen)
the momentum balance in fluid mechanics is super useful because it allows us to simply draw a control volume wherever we want in the flow and then compute the net force that’s applying to that fluid inside based just on measurements at the outlet and at the inlet however it’s also very intimidating and so let’s take a look at the different terms inside this equation we have here three different terms on the left is Fnet is what we want to calculate this is the net force the sum of all the forces due to a propeller inside or a compressor or due to shear inside the flow or due to pressure inside the flow due to gravity the net vector sum of all of those as one force this is what we want to calculate and this is equated to two things the first part is the change in time of the momentum inside the control volume and this is the sloshing back and forth this is, if you have a control volume with no inlet and no outlet but the fluid inside is going back and forth it still has movement and that distribution is changing with time then this will result in a net force on the fluid to this we add the net flow of momentum through the boundaries of the control volume this is the total sum negative in and positive out of all the flows carrying momentum with them inside the control volume so instead of trying to prove to you this equation let me try to show what it’s good for and what is not good for let’s take a case where we have only one Inlet and no it has only one Inlet and two outlets now like this what is this Vrel and this dot n vector in this equation so those terms here what are those for this is to designate the inlet or outlet velocity incoming outgoing velocity through the control surface through the surface of the control volume and so let’s imagine now that you have through this control volume this control volume in blue could be expanding or contracting could be moving the velocity of the fluid relative to the surface here V rel at the inlet one would be like this could be uniform for example what is V orthogonal or what is Vrel dot n what we’re looking for is the amount of velocity, the component of Vrel that is perpendicular to the area this is V orthogonal here and this Vorthogonal is following the direction of the flow so with it’ll be incoming when the flow is incoming it will be outgoing when the flow is outgoing and in this equation here Vrel dot n, the dot product of this relative velocity vector and a unit vector that’s pointing outwards every time, is the length it’s the length of V orthogonal and by convention in fluid mechanics this is very upsetting for thermodynamicists the orthogonal will be negative inwards and positive outwards okay let’s take a case where there’s only one Inlet and one outlet and let’s have a look at this equation the net force here is equal to the change in time here of the momentum inside the control volume plus whatever is going out here with density the component of velocity perpendicular to the surface and the vector velocity v2 as we do this integral here over the whole area 2 to make sure that we catch any non-uniformities in the velocity distribution and then minus the same thing for the incoming velocity.
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Computing the net force on a fluid with non-uniform velocity distribution
in this problem we’re taking a look at cases where the flow where the velocity distribution at the inlet and at the outlet is different and as a result a net force is exerted on the floor now we’re trying to compute this the answer to how to compute the net force on a floor like this one is found again using a very powerful a very general equation which is the balance of momentum equation in fluid mechanics this allows us to compute the net force here as a function of two terms one is the change in time of the momentum inside the control volume this would be for example the change of momentum due to the sloshing back and forth of water inside the tank yes inside of the control volume and the second term is the sum the net sum of the momentum flow coming in and out of the control volume what good is non-uniform velocity distribution math for?
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Calculating the net force on fluid flowing through a pipe bend
in this problem we’re looking at the flow of a chemical we have 200 kilograms per second of a chemical flowing through a pipe and the flow comes in horizontally 2 meters per second and then it swerves upwards through the bend of the pipe and exits vertically at 3 meters per second now what we’re looking for is the net force that’s applying on the fluid as it transits through the pipe to answer this question we need to work with the momentum balance equation and the momentum balance equation gives us the force, the net force like so if we can solve a rather long and torturous equation we say I’m gonna write here the way I like to write this equation is try to not remember every detail of it but remember the general structure and the general structure says that we have a change in time of an integral over the whole volume like so over the whole volume and to this we add an integral over the whole surface of the control volume and this is an integral with dA like so and the contents of those integrals change from equation to equation and so I’d like to not remember those in particular detail I just look them up in the formula sheet every time and so for net force we have here Rho times vector V like so and we have in this equation this surface integral here we have Rho V again the momentum per unit volume times this curious and rather annoying term which is the V relative; so the relative velocity, relative to the control surface dot the i vector which is a unit vector which is always pointing outwards like so and this integral here on the right is done over the control surface that’s a surface integral now this integral is very useful it’s very general you can use it in all kinds of cases actually I don’t know of any case where you cannot use this equation in fluid mechanics but it’s overkill for our problem and the equation we want to use for this particular case where is it there’s only one Inlet and one outlet and the flow is steady is it much simpler and it’s written like so in this case where we are if we have F net like so as a vector here is the mass flow multiplied by v2 the outlet velocity as a vector minus v1 the inlet velocity as a vector like so and we directly use this equation and start solving but I’d like to show you how to go from the top equation which is general and true for all cases down to this equation which is true for are particularly useful case here today but may not be generally true and so to do this let’s take a little time to go through this and let’s make the little space next so you push this guy down like so and let’s try to get from the top to the bottom of this equation see what we cross out in this big equation so the first thing we’re gonna cross out is this whole first term here here this is because this is the change in time of the momentum inside the control volume the momentum inside the control volume is not zero for sure but it’s change in time is because we have at the bottom here we have a flow that is completely steady the inlet and the outlet do not change at all the pipe is not expanding it’s not contracting you take ten pictures of this flow you will get ten times the same picture and so this whole component there let’s read it in light blue like so this whole component here this is equal to zero so this adds up to vector zero like so and then we have this a surface integral here and the surface integral is made over the whole control volume which in this case would circle around the pipe down here so something like this this would this would be my control volume let’s make a box like so yes would be my control volume over this whole area we do with this surface integral and so this comes down down to just two components one for internet and one for outlet let’s have a look at two things in there the first thing is this annoying term here Vrel dot n this is called the orthogonal and the orthogonal is going to be positive when the flow is outgoing and negative when it’s incoming these are the conventions we use in from mechanics so it’s just right here positive outgoing negative in like so and we’re going to leave the rest intact so let’s now write the rest of this equation here we have here minus the integral in coming here of Rho times the velocity vector here times here the absolute value of the orthogonal because V orthogonal here is negative when I put an absolute value here I have minus over there yes and this is for ta integral da this is for the inlet and for the outlet I’m gonna have exactly the same thing is there except it’s a plus and so this writes as integral out of again Rho vector V times here and then da like so okay so let’s try to work this some more we have the integral here when we look at the integral that we have we’re integrating with respect to area but when we look at the inlet of our control volume all the way down here then in there we have only one velocity vector a meaning in this simplified problem all the incoming vectors are all parallel and identical one to the other the velocity is uniformly distributed at the inlet this means that when we integrate anything with respect to area at the inlet they’re all going to stay constant with respect to area so this is really no need for an area for any real integral so this here adds up as being minus Rho vector V times the absolute value of V orthogonal here a and all of those terms are for the inlet so I add here the indices 1 1 1 in like so this is for the inlet and for the outlets here I have the same thing Row 2 vector V 2 like so then the absolute value of the orthogonal to and then e to myself and now here we notice that every time we have Rho times V orthogonal times a and again Rho the orthogonal a and this sums up here every time - of course mass flow so that we have I’m sorry I forgot the - here’s the - the mass flow multiplied by V 1 here and then plus the mass flow multiplied by vector v2 like so and so this of course adds up and sums up let me try to reduce now the space this here is equal to the net force mass flow multiplied by the difference between the outlet and the inlet and vectors ok so so much for the general theory now let’s try to solve the actual math let me take a little space here and move this to the top and let’s try to solve this general equation and to write out what net force is going to be in this case okay this equation on top is actually three equations this is because we’re in case where we have three dimensions XYZ so whenever I the vector here it actually means the three components of that vector and so we could write it like this we could say this is F net X with F net Y with F net set these are the three components of the vector F net and this is equal to dot m the mass flow it doesn’t have three components and then a vector and the vector is this the subtraction of those two vectors V 2 and V 1 and this vector has in the X Direction V 2 X minus V 1 X in the Y Direction V 2 y minus V 1 Y and in the Z Direction V - Zed is v1z like so okay so now to be able to figure out what F net is here we want to figure out what the components of the two velocities here are and so to do this we just fill in the numbers we have here the mass flow is 200 kilograms per second 200 and now let’s put numbers here V 2 X the X component of the outlet velocity when we look at the components here we see that V 2 is purely vertical and so V 2 X will be 0 V 1 X here would be 2 meters per second but pay attention v2 is going sorry V 1 is going in this direction so towards there yes well the positive x is going in the other direction towards there and so the length V 1 X is in the negative x direction and so V 1 X here is negative so when I subtract V 1 X here I’m going to subtract the value of minus 2 meters per second okay so V 2 y 2 y is the y component of V 2 and we can see that Y component is the direction here that’s pointing outwards of the screen so it’s going out of the video it towards you and nothing is happening in this dimension everything is 0 so I can straight away fill 0 for both of those components and then V 2 Z will be the component of in Z or with V 2 and so this is 3 meters per second is going upwards Z is positive upwards and so we have here 3 I could even write plus 3 like so and then the Z component of V 1 is 0 over here because V 1 is purely horizontal has no vertical component thanks so this adds up now as being 200 x plus 4 that’s 800 I’m sorry 200 multiplied by +2 so that’s 400 in the middle I have zero and at the bottom I have 200 multiplying by 3 which is 600 like so and this is f net and immediately yeah after I get a number I always check the result of units so units of force are Newtons and so let’s square this up at the bottom squaring is very difficult I’m new with this tool so I’m not exactly clean with my straight lines okay so this is how you solve with math calculating the net force applying to a fluid as it transits along now let’s try to see what this means and what this looks like with geometry with just lines looking at just the arrow to do this let me make a little bit more space let me shift this up yeah let’s have a look at what this F net really is f net is basically v2 minus v1 yeah there will be 2 minus V 1 vectors let me try to draw a nice and straight lines let me try to put them in blue like in this assignment we have here V 2 has a vector and we have here V 1 as a vector what is V 2 minus V minus V 1 as a vector well to answer this you take V 2 like so I mean put a straight line again let me try again I’m not so good at drawing when I’m going towards the bottom of the page v2 minus v1 so let’s try again drawing okay so we have V 2 like so this is V 2 and you put then V 1 at the end of V 2 you put actually minus V 1 at the end of V 2 this is minus V 1 what’s so and this will make the sum of those two vectors is then once put it in ready here let’s put it like so it will be a vector that goes like so yes yeah this is then V 2 minus V 1 has the vectors this you multiply this V 2 minus V 1 by the mass flow m dot and then you get the net force so that if we represent now the net force that’s applying to the fluid on the bottom here it would look something like this you start at a arbitrary point you go let’s have a look at the details again that’s 400 in X in 600 in Z so you go 400 in X and then 600 in Z and so this would be then something that looks like so sorry not very good at drawing yet I will improve with time but this is a little difficult for me now yes right so this would be here the net force that’s applying to this fluid here this is how you see visually what the meaning of the numbers and this in this result are 400 and 600 this is the net force that you need to apply to the fluid to make it as it comes from here and it leaves like that to make it change velocity from this to there who applies this force it may be several things might be the pipe it might be a machine inside the pipe it might be pressure and shear due to the fluid itself we don’t know we cannot know where the information that we have here all we know is that the net force is I’m sorry mm this direction like so as represented down there lastly if you want to know what the net force applied to the fluid sorry applied by the fluid to the pipe is then you take the opposite force and so the force applied by the fluid onto the pipe would be the opposite it would be something that looks like so here this would be the force of the fluid on the pipe what would be the opposite so with this this vector here in green will have minus 400, 0 and minus 600 Newtons of dimensions so there you go this is how you calculate net force with two inlets sorry two vectors one at inlet and one at outlet .
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Calculating the inlet height in a boundary layer control volume (Fluid Dynamics w/ Olivier Cleynen)
in this problem we’re taking a first look at boundary layer flow flow very close to surfaces in this problem we were in particular looking at air coming in and flowing over a flat plate and it’s coming in here from the left with a very nice smoothly uniformly distributed velocity 25 meters per second and it’s leaving towards the right and by the end of the plate it has now a very strange and complex velocity distribution that is not uniform anymore the question we’re trying to answer is what is the thickness of a control volume at the inlet that has the same mass flow as the thickness here has at the outlet it’s a bit of a strange question and so I’ll spend some time explaining what the question really means before I start answering it let me show you what the control volume could be to study this problem we could simply draw a rectangle on the bottom would be the plate and on top would be a straight line at the outlet you would have a velocity distribution that looks like this like so with progressively smaller arrows as you go down and then you would take this length here and we reproduce it here and this would be here the inlet velocity distribution there’s a problem with this control volume which is it doesn’t have a mass balance if you look at the mass flow exiting of the control volume here there’s deficit here this whole this whole velocity here is lacking if you went to integrate velocity with respect to area at the outlet you will not get the same number as in the inlet and so the question becomes where is this mass flow gone?
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Meet NASAs Next Earth Science Division Director
Hi, I’m Karen St. Germain, and I am thrilled to be NASA’s next Division Director for Earth Science. I hoped to greet you all in person today, but, that day will come soon, and in the meantime, I thought I’d introduce myself and tell you a little bit about my background and why I’m so excited to take on this role. I got my start in Earth Science up close and personal flying through hurricane Gilbert in 1988 as a graduate student at the university of Massachusetts.