"A Solution Looking for a Problem"

Last week I attended an engineering seminar entitled: From Mathematics to Medical Device Design. The presenter was very engaging, and I really liked the matter-of-fact way she talked about her personal history and current work.

I found it really interesting when the presenter discussed a project she had done as a graduate student at MIT. Her professor was tasked with creating a use for all the cork that Portugal generates. What I found fascinating was that she described this project as "a solution looking for a problem." I think that is a really cool way of looking at engineering. Paying attention to the excesses in the world is just as important as looking at the gaps in production when trying to solve economic issues. The result was an attempt at making wind turbines out of a combination of cork and plastic.

New Blog!

Hello again!

I'm announcing a new blog...Dam Management in Cape Verde: Soil Erosion!

For a final project in Extd. 120, my team is working with the Ministry of Agriculture in Cape Verde to research soil erosion surrounding the Poilao Dam in Santiago.

Check out our blog:

http://capeverdedammanagement.blogspot.com/

Stove Part V: testing!

Finally, we reached the last stage of the stove project: testing!

Our task was to try and boil water using charcoal. Each team used 1000ml of water and 200g of charcoal. We used a fire-starter to get the charcoal burning.

Here's a picture of the setup:

As the fire burned along, we noticed that the chimney was working, however its placement was not ideal. There is a reason chimneys always direct the air UP! It is not good to have a chimney horizontal to where your stove is. That aspect is definitely something we would change if we could.

Here is a picture of the stove from the other side:

We were pretty happy with how sturdy the stove remained with the added weight of the pot. Although the heating surface sank in a bit, it didn't topple over or really affect the structure of the stove at all. The doors worked well, except for the minor problem of them blowing shut with wind. We would definitely improve upon that design if possible.

In frequent intervals we checked the temperature of the water to see how fast and how high the water would heat. The water started out at 24˚C, and was put on the stove at 2:07pm. We ended the experiment at 3:08pm with a water temperature of 53˚C.

Below see a graph of the water temperature over time:

I'm pretty happy with this curve. I think we could have gotten the water temperature higher with some changes, such as making the design allow for the heat to be closer to the pot. This would have made the water heat up much faster, and maybe even make it boil.

Now that I am much more familiar with working with aluminum and actually building something with hinges and rivets, I think I could make a much cleaner stove that functions better than the one we completed. All in all, though, I am happy that our stove successfully heated water and didn't collapse under the weight of the pot. In regards to our goal of improving air flow, I think we did that quite well. The doors were a success, and the chimney, though it could have been better, served its function.

Thanks to Kelsey and Alex for all their hard work!

~FIONA

Stove Part IV: the final aluminum model!

The final stage of the building process was making the stove out of aluminum. Aluminum is a very interesting material. We used a very thin sheet metal, which meant it cut relatively easily, and bent relatively easily. However, its thinness also made it quite unstable. Therefore, the challenge was to make the stove actually hold up a pot. Stay tuned for the testing phase to see if we actually accomplished this!

We began by drawing to-scale drawings of each side of our stove. We then used this as a reference, and drew on the aluminum sheets with sharpie. We experimented with many tools until we each found which would cut the aluminum best in a given situation. I found that my favorite tool was an olfa knife. The olfa allowed me to cut in straight and curved lines very cleanly. When using the olf knife you don't have to worry about material getting caught and messing up your line, like you do when you use a snip. 

Below see some of the cut-out sides of our stove:

As you can see from the second picture above, we used a straight-edge to be accurate with our measurements. This tool proved very very useful throughout the aluminum-cutting process.

After cutting out all the necessary parts, we drilled holes in the aluminum and began to rivet the parts together. Here are some pictures of some of our drill work:

About halfway through the building process we let Amy know that we needed hinges and magnets for our stove. We decided on magnets as fasteners for our two doors, and hinges for those same doors. 

Below see pictures of our hinges and doors:

We decided to use aluminum tape as well as screws to secure the hinges to the door. We found we had to do this combine approach, because the door was clearly not as thick as a door in real life, so the screws really got in the way of the functionality of the stove. 

Before riveting the whole stove together, Kelsey made a wonderful tray for our charcoal. We then cut and bent shelves to hold the tray. Below see pictures of these:

And finally....*drumrolllllll*....here is the finished stove:

At this point, we were ready to test our creation. 

Check out the next post for the results!

Stove Part II: Cardboard Model

The next step in our stove-making process was to make a cardboard model of our design. This part of the process allowed us to really critique and change our design. It also helped us learn how to measure and cut material effectively and precisely. It is surprisingly hard to cut a piece of material into a square...let alone into a trapezoid!

We secured the cardboard together with duct tape in the model, which was convenient at the time, but also gave us a bit of a false sense of confidence in creating hinges and connecting pieces of material. It is much much easier to connect everything with duct tape rather than with hinges and rivets. Nevertheless, we cranked out a successful model.

Throughout the time we were working on this stove, we didn't really assign each other specific roles. Each of us really just worked on whatever needed to be worked on. We each realized what our strengths were, and I think we played off of those a bit in coordinating our teamwork.

Below are some pictures of the making of our cardboard model:

Above is a picture of the front of our stove, with the flap for air flow clearly visible.

And above is a picture of the finished base of our stove. After building this base we decided it would be a good idea to add shelves to the sides to allow for varying levels of heat. We made a tray for the charcoal to rest on, and three shelf levels to allow for low, medium, and high heat. 

Above is a picture of the side of the model, with the placement of the shelves drawn on the outside.

And above see a picture of the tray at the medium heat-level setting.

Above see the top of the stove. The surface that will be put on top of this trapezoid-shape will be where the pot goes. 

And here is the chimney!

Finally, here is the front of the finished model! I was really happy with how this turned out. It was almost even evenly-shaped, which is surprisingly hard to accomplish. 

This part of the stove-making process made me a more flexible builder. At first, I was resistant to changing our design, but in making the cardboard model I learned that you have to be really willing to change everything is something's not working. More iterations of the design = success!

....and on to Part III....dealing with aluminum!

Stove Part I: Brainstorming and Designing

And here begins the story of Fiona, Kelsey, and Alex's aluminum stove.

We began the design process with some visual brainstorming. Below are some of the sketches we came up with:

 We played with varying levels of heat, different sized grates for pots, and different overall shapes. In our design process we focused on improving air flow and maximizing heat. We decided that we liked the idea of a trapezoid-like top to the stove, so that the heat would be directed well towards and spread out well under the pot. We then decided a chimney would be an important facet for directing smoke away from the user, given how unhealthy and dangerous it is to inhale smoke. We decided to have a door so that we could vary the amount of air entering the stove. Below is a picture of our original design with original dimensions:

And below is a sketch of the front and back of our stove design:

 As you will see from our finished product, the stove design and dimensions changed quite a bit over time. In this part of the stove-making process, I think we did a good job combining the good ideas from all of our sketches.

Stay tuned for part II!

Too Many Joules!!

The latest assignment for Extd.120 is to calculate our energy use over the course of three days. The assignment is purposefully vague, to challenge you to think about every little thing that you use that uses energy. In my calculations, I chose to include time using/doing: lighting, laundry, laptop, phone, and printer. I consciously did not include meals, heating/cooling, and whatever else may use energy to help me live nicely. I didn't even know where to begin calculating those estimations.

First, here are some assumptions that I made in order to do the calculations:

Incandescent lightbulb = 60W

Room lighting = 3 bulbs

A room in academic buildings = 10 bulbs

Lulu = 50 bulbs

Bates = 50 bulbs

Campus Po = 50 bulbs

In calculating the number of bulbs in Lulu & Bates, I estimated only immediate lighting. So, only lighting that would have directly affected what I was doing in that space. If I had calculated the lighting of the entirety of each building, my total would have been way higher. 

Printer = 2x the power required to run a laptop (60W - see previous blog post)

Phone = 1/8 the power required to run a laptop

Power required to do laundry = power required to run fridge (14,400W - see previous blog post)

Below are my results!

(sorry about the formatting issue...)

Grand Total: 205,362,000J

That is a lot of joules....I was amazed at how much larger the Monday total turned out compared to Sunday & Tuesday. It seems that laundry makes a huge difference. Also, time spent in my room is energy wasted. Lights are on in the public buildings no matter what, whereas having lights on in my room is a choice. This data definitely made me do a double-take...and this is only over 3 days!

	Sunday	Sunday (calculations)	Sunday (totals)	Monday	Monday (calculations)	Monday (totals)	Tuesday	Tuesday (calculations)	Tuesday (totals)
Hrs of lighting in room	1.5 hours	3bulbs X 60W = 180W. 180W X 5400sec. = 972,000J	972,000 J	3 hours	180W X 10800sec. = 1,944,000J	1,944,000J	1 hour	180W X 3600sec. = 648,000J	648,000J
Hrs of lighting in Jewett	4 hours	10 bulbs X 60W = 600W. 600W X 14400sec. = 8,640,000J	8,640,000J	2 hours	600W X 7200sec. = 4,320,000J	4,320,000J	5 hours	600W X 18,000sec. = 10,800,000J	10,800,000J
Hrs of lighting in Sci Center	4 hours	10 bulbs X 60W = 600W. 600W X 14400sec. = 8,640,000J	8,640,000J	6.5 hours	600W X 23,400sec. = 14,040,000J	14,040,000J	4 hours	600W X 14,400sec. = 8,640,000J	8,640,000J
Hrs of lighting in Lulu	2 hours	50 bulbs X 60W = 3000W. 3000W X 7200sec. = 21,600,000J	21,600,000J	2.5 hours	3000W X 9000sec. = 27,000,000J	27,000,000J	2.5 hours	27,000,000J	27,000,000J
Hrs of lighting in Bates	0.5 hours	50 bulbs X 60W = 3000W. 3000W X 1800sec. = 5,400,000J	5,400,000J	0.25 hours	3000W X 900sec. = 2,700,000J	2,700,000J	0.25 hours	2,700,000J	2,700,000J
Hrs of lighting in Pendleton	0 hours	0	0	2 hours	180W X 7200sec. = 1,296,000J	1,296,000J	2 hours	1,296,000J	1,296,000J
Min of lighting in Campus Po	5 min.	5bulbs X 60W = 300W. 300W X 300sec. = 90,000J	90,000J	5 min.	90,000J	90,000J	0 min.	0	0
Min of printer	5 min.	120W X 300sec. = 36,000J	36,000J	0 minutes	0	0	0 min.	0	0
Hrs of phone	2 hours	7.5W X 7200sec. = 54,000J	54,000J	2 hours	54,000J	54,000J	2 hours	54,000J	54,000J
Hrs of laptop	6 hours	60W X 21,600sec. = 1,296,000J	1,296,000J	6 hours	1,296,000J	1,296,000J	6 hours	1,296,000J	1,296,000J
Hrs of laundry	0 hours	0	0	1.5 hours	14,400W X 5400sec. = 77,760,000J	77,760,000J	0 hours	0	0
			Sunday Total: 46,728,000J			Monday Total: 106,200,000J			Tuesday Total: 52,434,000J	Grand Total (3 days): 205,362,000J