Category Archives: Learning & Teaching

Closed system on BBQ

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sausagecloseupMy post of December 21st, 2012 on ‘Closed systems in nature?’ is my most popular  based on the statistics from WordPress.  These statistics led me to go back and read it again, which set me thinking along the same lines while tending the barbeque in our backyard.  A sausage is a nice example of a closed system with a boundary, or skin, that is impervious to mass or material moving across the boundary but which allows energy transfer in the form of heat.

Heat transfers into the system [sausage] through the boundary [skin] adjacent to the hot charcoal in my barbeque and heat transfers out on the opposite side.  Heat is simply energy transfer that occurs along a temperature gradient or across a temperature difference, from a higher to a lower temperature.

The temperature difference between the hot charcoal at about 375 degrees Centigrade and a sausage starting to cook at about 70 degrees is larger than the difference between the sausage and the air above it at say 35 degrees Centigrade, so more heat [energy] is transferred into than out of the sausage.  The difference between the energy in and out is used to heat and cook the sausage including starting to boil the water-content and trigger chemical reactions associated with cooking.  This is a manifestation of the first law of thermodynamics for the closed system, i.e. heat transfer in minus heat transfer out equals the change in the energy content of the system.  The net flux of heat into the sausage causes it to get hot and be cooked.

You can’t avoid thermodynamics, it gets involved in everything!

Bridging cultures

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cpsnowAs long ago as 1959, Sir Charles Snow identified two cultures in modern society, which could be summarised as those that understand the consequences of the second law of thermodynamics and those that don’t [see my post entitled Two Cultures on March 5, 2013].

The main aim in writing this blog is to help in bridging the gap between these cultures by commenting on and explaining engineering concepts, ideas and principles in a way that non-engineers can appreciate and might read.  One of the reasons for the gap between the cultures within our society is that ‘technology is really a way of thinking’ [see reference below].  Engineering educators spend a lot of time teaching prospective engineers how to think and, in particular, how to solve engineering problems.  However, these same educators often forget when introducing engineering students  to the principles of engineering for the first time that the students are not familiar with the language or culture.  The students are just starting to cross the gap and their educators, who are on the other side of the gap, fail to appreciate the width of the gap.  The result is that educators fail to engage the students which results in poor recruitment and retention of engineering students.  This failing is recognised by some people, see for instance http://www.engageengineering.org/

One solution to help students cross the gap is to use familiar everyday examples to explain engineering concepts.  I have made a short video about the underlying pedagogy together with some examples that you can find at http://www.youtube.com/watch?v=qAh4QHC8ya0&feature=youtu.be .  There is also a series of booklets [ http://www.engineeringexamples.org/ ] designed to support university teachers who want to teach in this way.  I plan to rewrite the examples in these booklets as periodic posts on this blog for a wider, non-technical audience.  So watch this space!

‘Technology is really a way of thinking’: http://www.atse.org.au/Documents/Publications/Reports/Education/ATSE%20Technology%20Education%20A%20Way%20of%20Thinking%202004.pdf

Innovation jobs

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Yesterday, I listened to an interesting talk by Dr Liang-Gee Chen, President of the National Applied Research Laboratories of Taiwan at the UK-Taiwan Academic-Industry & Technology Transfer Collaboration Forum organised by the British Council.  He presented some statistics from the Kaufmann Foundation [http://www.kauffman.org/research-and-policy/business-dynamics-statistics.aspx], which demonstrated that nearly all new jobs in the USA are generated by new companies.  When you combine this with my conclusion in my posting on ‘Population crunch’, that we need a higher level of innovation in engineering, then we need to review the education programmes provided for our engineers to ensure that they include innovation and entrepreneurship.  These need to be integrated in engineering education programmes [see Handscombe et al, 2009].  We seem to have lost the plot in the UK and retreated to teaching engineering science, design and management orientated towards the employers with the loudest voice, i.e. multi-nationals, who are not likely to be the source of innovation jobs that will pull us out of the global recession.

Handscombe, R.D., Rodriguez-Falcon, E., Patterson, E.A., 2009, ‘Embedding enterprise in engineering’, IJ Mechanical Engineering Education, 37(4):263-274.