January 31, 2007, by Teaching at Nottingham

Demonstrating principles using activities in lectures

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Kate: “The last thing I wanted to ask you about was the demonstrations and bringing that into a classroom. What are the pros and cons of doing something like that, do you think, in terms of for the students and for the lecturer?”

Ed: “The con might be that it goes wrong. There is one particular module where I sing a song, I bring my guitar in and I sing them the biochemical pathway. The con is that it goes horribly wrong and they decide that you’re an idiot and they don’t like the lecture, they don’t respect your style, they don’t participate and there is a cold silence. That is the possible problem.

“The benefit is that everybody is going to remember from this demonstration certain fundamentals and the fact that the course has a specific element in it about this, and the exam will have a question in it as well.

“I would like to think that when they take the exam they will be able to remember certain important features that they had demonstrated.


“What we’ve got here is a factory, it has four different types of stack, different diameters, different heights it’s making some kind of blue goo, we don’t know what it is, but what it is missing is a site foreman, so I asked my children about this yesterday and they were very helpful.
What we have got is different size stacks, so that one relates to the top one and we will try a few different things to see how we can vary what is going on with this list.

“In theory this should work.

“Slightly leaky! It could be on fire, we are not quite sure! It takes a while to get it going, but what you can actually see is it’s a fairly good plume up to about there and then it starts to diffuse, and there is not a whole lot of wind in this room.

“This is where it is now drifting past the fire alarm and it doesn’t seem to be going off at the moment. So what we can do is pull the cap off. What you can see is that the plume makes it in a fairly distinct form for quite a long way.
“I need a volunteer at this point. He’s volunteered you, which is very noble of him.
“Can you come down for a minute? We are going to artificially make wind. Perhaps I didn’t phrase that very well, or maybe I did!”

To student: “Do you want to take that.”

“Now we have the ability to make cross wind with a highly technical device called a hairdryer. This light has now gone off, you just need to wait there for a minute.

“Now we need some cross wind – direct it in his direction because he volunteered you for this!

“Now whilst it’s quite thin, you can see if you have a fairly good cross wind, although it’s not to scale obviously you can start to manipulate where this plume is going, in this case straight to you (I think she is taking it too seriously though!). I am just going to put that back.
Now if we go back and try this one, this is a fairly short stack. Stand back there then. No, right back there.

“So we have proved the point then that we can manipulate the height at which the plume reaches and we are going to look at what effective stack height means in relation to plume height. What I thought it would be good to do, is to see if we can deliberately contaminate certain countries with our plume.

“In order to do that I thought I would print off, because we are obviously multinational here at the University of Nottingham, I have printed off a few flags, and I thought I would position you at set distances and see if we could get to you and dissolve your trees.

“Which flag is that? Oman OK then, isn’t it amazing how you knew your own flag!


“It doesn’t have to be perfect, it doesn’t look very good either but it does demonstrate certain principles and they will remember it too.”

Ed Lester
Department of Chemical & Environmental Engineering

Ed is teaching engineering students on a module about environmental protection (H8BENP Environmental Protection, Level B). Produced January 2007.
This video was originally published as part of PESL’s Teaching at Nottingham collection.

Posted in Lectures