Adventures in Science

Posts tagged ‘electricity’

Awesome Heros Wield Pee Power

Duro-Aina Adebola, Akindele Abiola, Faleke Oluwatoyin, and Bello Eniola engineered this generator that turns urine into electricity.

(source)

A group of four girls ages 14-15 demonstrated their urine-powered generator at the recent Maker Faire Africa in Lagos. The girls’ project also generated a lot of excitement and interest on the web over this last week. Although it won’t be able to compete with the energy output of coal or gasoline, this technique puts forward the possibility that urine could be tapped as one of many (cough) um, clean energy sources. There is probably a stinky pee smell, but clean in this case means it doesn’t give off CO2 emissions or other pollutants.

Let’s take a look at their process—

The Maker Faire Africa blog listed their method as such:

  • Urine is put into an electrolytic cell, which separates out the hydrogen.
  • The hydrogen goes into a water filter for purification, which then gets pushed into the gas cylinder.
  • The gas cylinder pushes hydrogen into a cylinder of liquid borax, which is used to remove the moisture from the hydrogen gas.
  • This purified hydrogen gas is pushed into the generator.

Along the whole way there are one-way valves for security, but let’s be honest that this is something of an explosive device…

The generated electricity powers a light bulb which is mostly hidden by the middle girl’s knee in the picture above.

The girls designed their system based on this paper by scientists from the Department of Chemical and Biomolecular Engineering, Ohio University. Here is a more reader-friendly article on the paper that you might want to check out before you decide to explore the  scientific paper.

There is also a good deal of scientific debate and skepticism over whether this is a useful or effective electricity generator. The comment thread below that blog post is a good sampling of the discussion.

Good science means hashing out the truth and not taking claims at face value.  The only way to know for sure if this process works is to replicate the girls’ setup. With appropriate mentoring and safety precautions, it would be great to see other kids working to recreate this idea. If it turns out that this works…awesome! Then young scientists can work to make improvements to the technique.

We look forward to the day we can feature the work of the first group of teens that powers a cell phone from this kind of pee-powered system. Game on.

Awesome Hero–The Boy Who Harnessed the Wind

William Kamkwamba, Awesome Hero

(source)

William Kamkwamba was born to a farming family in Malawi in Africa in 1987. His home and the homes of his neighbors didn’t have electricity or running water. The family’s crops depended on the amount rainfall that they received because their farm had no irrigation. When he was 14, a horrible drought struck Malawi  and the crops failed. Many Malawians died of starvation. William and his family survived but suffered horrific deprivation. His father was deep in debt from buying food for the family so couldn’t afford tuition. William had to drop out of school.

After surviving the famine, William was inspired by a textbook he borrowed from his local library called Using Energy to build a windmill to make electricity and eventually pump ground water from a well to irrigate the family’s farm. He was determined to give his family a more secure food supply with two maize harvests a year as well as an irrigated garden for a variety of vegetables.

William Kamkwamba slowly built his windmill from salvaged and modified scrap material. He describes how he did it in his autobiography The Boy Who Harnessed the Wind. The ingenuity involved in the design and construction of his windmill is astounding. This book is *highly* recommended to all young people over the age of 12. Read it. Listen to it. Do it.

There is also a picture book version of William Kamkwamba’s story for younger children because it is *that* good.

Exploring Magnetic Fields

At explainthatstuff.com there is a great explanation of magnetism and magnetic fields for kids by Chris Woodford. If you read that first you will get more out of this post. At the bottom of this post I’ve included a link to a more advanced video on magnetic fields from khanacademy.org for those who want a more detailed explanation.

Now let’s play…

Let’s explore the magnetic field or region of space around magnets in which the magnetic force occurs to get some insight into what it is like and how it works. Most of the time magnetic fields are invisible to our eyes. The demonstrations in the following videos help us to see the lines and curves of force of magnetic fields around different types of magnets.

First is this video from funlearners channel on YouTube:

Here we can see some slices through the magnetic field with all of the little compass pointers on the plexiglass lining up. Plus we can see that the magnetic field changes shape with the two differently shaped magnets. You really get a sense of the 3-D shape of the field when the bar magnet is in the middle and the man spins the viewer.

Here is a 3-D magnetic field viewer by wbeaty that you can make yourself:

Easy peasy! Try not to touch the steel wool slivers that you cut off too much. Instead of picking them up with your fingers just cut them over a sheet paper and then pour them into the bottle down the crease of the paper folded in two. Also, rinse your fingers after working with the steel wool to avoid nasty metal slivers in your skin or eyes.

Experiment with your 3-D magnetic field viewer using one, two or more magnets. Try different shapes and types of magnets to see if and how the fields differ. Carry your viewer around the house and see if you can spot a hidden magnetic field. Then try to figure out what is causing it.

This video from KJMagneticsProducts is what happens when you stick a powerful magnet into magnetic paint:

That magnet is going to be hard to get clean again. That paint is wet, but the particles of iron pile up on each other in the shape of the lines and curves of the magnetic field until it looks solid. There are many videos on the internet showing ferrofluids, which are liquids that become strongly magnetized by a magnetic field. Ferrofluids display the beautiful geometries and movement of magnetic fields. We will revisit ferrofluids in a future post on OGLoA. Until then, go look them up. You won’t be sorry!

For the older kids, if you have an old-style computer monitor just lying around, research how it can be made into a magnetic field viewer. Get permission from your parents first!  Here is a great one featured in this video by YoungTesla:

Move over LavaLite, we’re going to make one for parties! YoungTesla has three magnet/computer monitor experiments on his YouTube channel and lots more. Check it out.

As promised here is more on magnets and magnetic fields from KhanAcademy.org:

Introduction to Magnetism

Khan Academy is a wonderful web site for self-study or to use as another source of information when you are stuck on a topic in your school work.

What is electricity? (pt. 1)

"Night Carnival" (c) 2001 Bob Crosby

Even though we have been using electricity to power our gadgets, tools, and lights for over 100 years it still seems like magic. Why is that? Maybe because in our everyday lives, when electricity is being used correctly, we can’t feel it, see it, or hear it until it causes something to happen, like the toaster to heat up, the light to turn on, or the iPod to play a great song. Fortunately, just because we can’t always experience something first hand, does not mean it doesn’t exist and cannot be explained.
This will be a very basic explanation of electricity for beginners. One Giant Leap of Awesome will do another more advanced explanation of electricity in another entry.

Let’s begin!  

First of all, you need to know that the tiniest pieces of matter– the stuff that everything is made of–are called atoms. All of the matter in the universe is made up of over 100 different types of atoms.

Below, is a drawing of an atom.  Atoms are round like a dandelion puffball. They are made of two main parts. The first part is the central area called the nucleus. In the drawing below it is the small, darker grey area in the middle.  The part of the atom that causes electricity is found in the blue, fuzzy outer part in the drawing. That part is fuzzy because that is where the electrons live in the atom.

This picture is a drawing because atoms are so small we can’t see them and they are too small to get a good picture of them. 

If you visit the “Scale of the Universe” site and move the slider to the left (smaller-than-human-size direction) you will find the size of atoms and electrons between the “•v” and the drawing of a dot with ovals around it which is a cartoon atom.

http://primaxstudio.com/stuff/scale_of_universe/

Electrons are jumpy and hyper. They like to MOVE. If we had cameras small enough to take pictures of them they would still look blurry because they never sit still.

Electrons don’t just stay put on one atom either. They love to piggyback and hopscotch onto other atoms and, given the chance, they will stampede from atom to atom.  When they stampede from atom to atom we get electricity.

 Also, they are super fast! To give you an idea how fast, a flash of lightning is a GIANT electron stampede!  The entire stampede takes a split second. In that small length of time, sickzillions of electrons stream through the sky in a jagged line.

I have a confession. Sickzillions is not a real word for a huge number.* I made it up because this is just how many electrons we are talking about:

15,600,000,000,000,000,000,000

That is also known as 1.56 x 10^20 which is pronounced: one point five six times ten to the 20th power.

OR

Electrons to the power of SICK!

Whiz-BANG!!

The amazing thing about jumpy and unruly electrons is that we have learned to control and use them. When a stampede of electrons goes in one direction–like how the water in a river flows from high to low—they make an electric current which we can direct and tap into to work for us.  It is a bit like how people in the past learned to use the power of a river’s current to turn a paddle wheel for their grain mill. 

 One of the ways we control electricity is by using special pathways for electrons to travel through. People figured out that electrons prefer to stampede through special types of elements that became known as conductors. For example, we use copper to make pathways of electrical wiring to direct currents of electrons to power our machines.  Most of the electrical wires in our machines have copper cores.  Some other elements that electrons like to flow through are silicon, silver, lead, gold, platinum, and mercury.

Okay. So now you know that electricity is caused by tiny parts of atoms called electrons that like to hop from atom to atom and often flow together in a current. Part 2 of “What is electricity?” will explain what causes the jumpy and hyperfast electrons to stampede.

*I think that number above would officially be in the hexillions.