Podcast – Curious Cat Science and Engineering Blog

Clay Water Filters for Ghana

curiouscat — Mon, 13 May 2013 17:13:26 +0000

Pure Home Water, Ghana manufactures and distributes AfriClay Filters in an effort to bring clean water to 1 million people. So far they have delivered filters to provide 100,000 people clean water.

The process is simple. Water is placed in a clay filter and gravity pulls the water through the pores left in the clay during firing.

Sediment and bacteria are filtered out in several ways:

Physical straining: the particles are too large to fit through the pores in the clay
Sedimentation or adsorption: particles come to rest on or stick to the clay
Inertia: friction in the pores keeps the particles from passing through

Bacteria are also killed by a coating of colloidal silver (a disinfectant), which we apply to all filters that pass our quality control tests. While sediment and bacteria are filtered out, the molecules of water are small enough to pass through the pores in the clay.

The filters are sold to those who will use them. The effort has shown a willingness to pay by villagers in remote Northern Ghana (those earning < US$1/day). I imagine (I am just guessing) the prices are subsidized; in the last decade more (most?) appropriate technology solutions will have those benefiting pay something for the benefits they receive. My nephews are working on a similar effort in India, using bio sand filters, I plan to post more on that later. There is current a campaign to help fund the delivery of water filters to Indian villages.

Make Crosswalks More Visible

curiouscat — Tue, 25 Dec 2012 15:28:07 +0000

Good simple idea. And then executed well – for nighttime at least. Crosswalk lights up when in use giving drivers a more visible clue to stop.

The Science Behind Hummingbird Flight

curiouscat — Fri, 24 Aug 2012 07:45:21 +0000

Aerodynamics of the hovering hummingbird

Hummingbirds and insects have evolved for sustained hovering ï¬‚ight from vastly different ancestral directions, and their distinct phylogenies underlie the differences in their aerodynamic styles. In all other birds—and, presumably, hummingbird ancestors—the downstroke provides 100% of weight support during slow ï¬‚ight and hovering. Given that many birds possess the mass-speciï¬c power (using anaerobic metabolism) to hover for short periods, the selective pressure on hummingbird ancestors was probably for increased efï¬ciency (resulting in stiff wings with greatly simpliï¬ed
kinematics), and an upstroke muscle (the supracoracoideus) that makes the recovery stroke rapid, while contributing enough to the hovering power requirements to allow the downstroke muscle (the pectoralis) to operate within its aerobic limits.

In other words, this pseudosymmetrical wingbeat cycle is good enough, and although hummingbirds do not exhibit the elegant aerodynamic symmetry of insects, natural selection rewards ‘good enough’ as richly as it does our aesthetic ideals

Great Webcast Explaining the Digestive Systems

curiouscat — Sat, 11 Aug 2012 04:55:11 +0000

You will learn things like why it is so important to chew your food well (increase the surface area for enzymes to get at the food). Our bodies also have adapted to provide a huge surface area for the digestive system to work; the small intestine alone has a surface area of 250 square meters (larger than the size of most apartments). Your small intestine is 4.5 to 10.5 meters long.

Landing Curiosity on Mars

curiouscat — Sun, 15 Jul 2012 23:07:26 +0000

Touchdown on Mars will take place August 5th, 2012 (PDT or August 6th EDT and GMT).

Scientists Singing About Science

curiouscat — Sat, 30 Jun 2012 09:02:37 +0000

Fun video with scientists singing about science.

More scientists singing science songs: Friday Fun, Large Hadron Rap – Cambrian Explosion Song – The Sun is a Miasma of Incandescent Plasma – Protein Synthesis: 1971 Video

Video of Young Richard Feynman Talking About Scientific Thinking

curiouscat — Tue, 15 May 2012 22:55:48 +0000

The enjoyable video above shows a young Richard Feynman discussing how scientific thinking can advance our understanding of the world.

Lean Science: Using Cheap Robots to Aid Research

curiouscat — Wed, 21 Mar 2012 12:05:48 +0000

Fun video showing how scientists use Lego Mindstorm robots to aid research into creating artificial bones. Lego Mindstorm robots are useful at a very reasonable price.

The webcast also includes this practical quote from Michelle Oyen, lecturer in the Department of Engineering at Cambridge University: “without your bones you would be a pile of goo lying on the floor.”

The thinking discussed in the webcast echos the lean manufacturing principles discussed in the Curious Cat Management Improvement Blog: finding good solutions to aid people in doing their jobs. The type of custom solutions they discuss here are great.

This type of use of technology is great. One of the problems we often see with technology solutions though is when they are imposed on the workplace in a way that doesn’t aid people. There is a big difference between what Toyota does (using robots to make people’s jobs easier) and what others do in trying to copy Toyota (using robots to eliminate jobs). Lean manufacturing stressed the importance of using brainpower people bring to work every day. You want to use technology to enable people. These scientists understand that. Unfortunately many managers don’t.

Photosynthesis: Science Explained

curiouscat — Tue, 20 Mar 2012 12:49:50 +0000

Another very good webcast on a science topic from Crash Course. It is packed with info, thankfully you can pause and rewind as much as you need. Well normally you can, YouTube decided to not let me do that just now