Monday, March 30, 2009

Adventures in Engineering

Things are moving along quite quickly here in Kenya – so quickly in fact that I realize we’re close to ending our third course and I have yet to write one word about it.  This is partly not my fault:  this course, entitled “Global Technology”, ended up being rather short due to various time constraints – in total we’re spending only 15 days – a bit over 2 weeks.  This also means that each of those days needs to be jam-packed with lectures, labs readings and assignments, so it’s been quite busy.

Our lecture / reading material has spanned the range from talking about the IMF and World Bank and how they affect development, to discussing the technical specifications, cultural acceptance, financial limits and practical implementation of specific technologies (clay-based water filters, solar ovens, foam-panel housing, solar panels, etc.), to examining the important physical properties of materials and how and why these materials fracture (and what can be done to prevent it).

However the large majority of our days are not spent in the classroom, but outside in the “lab”.  To ground all of the theoretical discussions (and have a bit of fun), we’ve been working on some small-scale, handmade, very practical projects (cue photos).

For our first project we took a mixture of two different clay-based soils from Mpala, mixed it with gathered straw, and molded and dried bricks with different straw percentages.  We’re now testing the bricks for thermal insulation and heat storage properties to determine which would make the best building material for low-cost housing.

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Our second project involved heat treating bamboo and designing, machining, and wiring our own lamps:

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In addition to the passive solar techniques we explored with the mud bricks, we also did some observations/calculations/small experiments with solar panels, including checking out some of Mpala’s own arrays:

IMG_2318Our most delicious experiment to date involved using a solar drier built by an engineer here named John (who used to work for Cascade Designs and was the principal designer of this).  The oven was for drying grass/dung samples for researchers, but we decided to check out its effects on mangos, bananas, papayas, and tomatoes:

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The results were so good that we decided to take up solar driers/ovens as our final project.  We went to Nanyuki today to buy all of the materials, and spent 5 hours this afternoon working to put it all together using hammers, nails, saws, screws, chisels, planes, files, and a power drill (our only power tool).  They’re not quite done yet, but we should finish them tomorrow!  When we do we’ll start performing experiments to determine how various factors affect temperature variations and drying effectiveness, all of which will involve drying and eating more fruit ;) (I can’t wait…).

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  1. you ate dried fruit from an oven that dries dung?

  2. Yup.

    The dung samples are all kept in closed plastic bags (the idea is actually to pasteurize them, not to dry them), so the oven is clean and uncontaminated. I guess it is a bit strange though...