Category Archives: Learning & Teaching

Problem-solving in thermodynamics

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Painting from Okemos High School Art Collection at MSUDuring November and December I was handing out a sheet of problems every week in my first-year undergraduate thermodynamics class so that students could evaluate and refine their understanding and problem-solving skills as the course progressed. Of course, most students will not have done this and those problem sheets will have been part of their list of good intentions, which have now become part of their revision schedule. Well, perhaps?  Anyway, to help them is attached ‘Professor Patterson’s Patented Problem-solving Procedure (PPPPP)’ for entry-level thermodynamics problems.

PPPPP is written in the context of thermodynamics but actually it is what engineers tend to do when faced with analysis problems, i.e. draw a sketch including all the known information, identify some simplifying assumptions then apply and solve the relevant physical laws. There is plenty of research that shows most of us are visual problem-solvers [e.g. Martin & Schwartz, 2014] but it is remarkably difficult to persuade people to summarize a problem pictorially.  It takes practice and that’s why we give students lots of problems on which to hone their skills.

See my post entitled ‘Love an engineer‘ on September 24th, 2014 for about creative problem-solving engineers.  Or ‘Mind wandering‘ on September 3rd, 2014.

Sources:

Martin, L., & Schwartz, D.,  2014, ‘A pragmatic perspective on visual representation and creative thinking’, Visual Studies, 29(1):80-93.

Painting from Okemos High School Art Collection at MSU

Life takes engineering

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changingconversationTeachers change lives.  Doctors cure, nurses care. Firefighters are heroic.  What do engineers do?  Engineers shape the future.

Most of the things that engineers do are taken for granted.  I would like to think that we are so good at it that people don’t notice anymore.  Occasionally things go wrong and we get the blame but almost everything you do in life from the moment you are born is shaped by engineering.  A structural engineer designed the structure in which you were born, a team of mechanical engineers designed the vehicle you made your first journey in, if you needed medication a team of chemical engineers designed the factory that produced them and so on through life.  You can repeat the process for an average day – who designed the production system that made the bed you slept on, the alarm clock that woke you, runs the utilities that provided hot water to wash in, designed the supply chain that delivered food to your breakfast table and so on through the day?  Yes, engineers.

Maybe engineering is so ubiquitous that it is difficult to grasp its essence.  The engineering community spends hundreds of millions of dollars annually to promote public understanding of engineering with little measurable impact on young people, according to the US National Academy of Engineering.  Their report called ‘Changing the Conversation‘ recommends using four tag-lines to promote engineering:

1. Engineers make a world of difference.

2. Engineers are creative problem solvers.

3. Engineers help shape the future.

4. Engineering is essential to our health, happiness and safety.

About 40% of their survey groups found these tag-lines ‘very appealing’.  So perhaps none of them really resonated.  Oh, but now I am being an engineer and analysing the data in order to make a very rational, reasoned decision when instead I should be employing my creative, imaginative side.  Maybe we are back to poetaster engineers [see my posting on ‘Poetasting engineers‘ on March 4th, 2015].  As a profession we are not good with words [see last week’s posting entitled ‘Reader, Reader, Reader] and cannot dream up a catchy memorable tag-line.

What do you think?

Where there is muck there is an engineer

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Dr Lou Balmer-Millar at the FPC 2015 & the CAT 366E

Dr Lou Balmer-Millar at the FPC 2015 & the CAT 366E

Here’s a second post on what engineers do [see my post entitled ‘Press button for exciting ride‘ on March 25th, 2015].

Dr Lou Balmer-Millar leads a team that develops new technology for off-road vehicles.  She is Director of Research and Advanced Engineering at Caterpillar Inc. and she gave a keynote talk at the  Future Powertrains Conference, which I wrote about a couple of weeks ago.  She talked about the innovations that Caterpillar are developing to increase the efficiency of their vehicles.  This includes driverless giant trucks.  If you are worried about driverless cars then what about driverless 226 tonnes trucks?  It is already a reality –   watch the Caterpillar video.

However, what stuck in my mind from her presentation was not the enormous mining trucks but the way in which Caterpillar measure the efficiency of their diggers, such as the CAT 366E Hybrid.  They are not so much interested in miles per gallon as tonnes of dirt (or muck) shifted per gallon.  Efficiency is defined as what you want out of a machine divided by what you have to put in to a machine, or work done for energy supplied [see post entitled ‘Energy efficiency‘ on June 18th, 2014].  So for a passenger car, miles travelled divided by energy used is a reasonable measure of efficiency.  But for digger, tonnes of earth moved is what you are want done, so tonnes moved per gallon is the right measure of efficiency.   The machine in the picture does not look like anything special but Caterpillar claim it is 30% more efficient than its competitors.

So there is money to be made in shifting earth more efficiently than your competitors.  If you enjoy watching machines move earth the watch this video.

Photo credit: Joshua Tucker http://www.apcuk.co.uk/2015/03/future-powertrain-conference-2015-report/

Trees are made of air

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162-6273_IMGYes, it is April Fools Day but I am serious.  Trees are made of air.  Think about it.  What happens when they are burned?  You are left with a small pile of ash.  So where did the rest of the tree go?  When the tree ‘is burned, in the flaming heat is released the flaming heat of the sun which was bound in to convert air into the tree’.  These words are from Richard Feynman, who explains it much better than me.  Watch him on Youtube.

Sources:

Max Tegmark, Our Mathematical Universe, Penguin Books Ltd, 2014.

National Public Radio blog