|A group of UC San Diego engineering students has joined the ECOLIFE Foundation to develop technology that will help reduce the need for bushmeat hunting in Uganda while maintaining the diets of local inhabitants. Back row from L to R: Henry Chen Loc, Peter Cottle and Rachel Bruno. Front row from L to R: Wesley Chen and Vanessa Lai.|
San Diego, CA, March 14, 2011-- In the jungles of Uganda’s Bwindi Impenetrable Forest live half the world's population of mountain gorillas. It is one of the most biologically diverse areas on earth. However, in many parts of Africa wild animals such as gorillas serve as a major source of protein for local inhabitants. But as human populations increase, overhunting is a major threat to the survival of these species.
A group of UC San Diego engineering students has joined the San Diego-based nonprofit ECOLIFE Foundation to develop technology that will help reduce the need for bushmeat hunting while maintaining the diets of local inhabitants. They are doing this by building a sustainable aquaponics system for local communities in Uganda. Basically, the system circulates water between vegetable and fish (in this case, tilapia). The nitrogen from the fish makes the vegetables grow quickly and the plants clean the water for reuse by the fish. The system yields fish for high-quality protein and enough vegetables to allow excess to be sold in the market.
“Aquaponics is a sustainable food production system that links hydroponically grown plants and fish in a symbiotic cycle,” explained Vanessa Lai, a UC San Diego mechanical and aerospace engineering undergrad involved in the project. “The fish release byproducts in the water which is then converted into vital nutrients for plant growth. The plants absorb these nutrients and essentially filter the water. The water is then circulated back to the fish and the cycle repeats.”
Existing aquaponics systems use a bell siphon to create intermittent water flow to prevent the plant roots from becoming water logged, yet existing systems are prone to intermittent failure due to variable water flow rates. The students designed a high reliability bell siphon for ECOLIFE Foundation’s existing aquaponics system. Due to possibly unreliable power sources in Uganda, the students needed to design a siphon that is highly reliable, made of inexpensive material, and robust enough to work with low and high flow rates into the system’s reservoir.
A tipper/siphon designed by UCSD engineering students will be used in an ECOLIFE aquaponics system in Uganda. To see a video of how the system works, click here.
“Thus we implemented a tipper which decouples the flow rate from the pump and the flow rate out from the bell siphon,” said student leader Rachel Bruno. “So no matter what rate the water is filling the tipper the bell siphon will start and stop reliably. The tipper itself works based on a simple understanding of forces. In its upright (at rest) position, the tipper has more weight below its pivot. As the tipper fills with water, the center of mass of the tipper begins to move above the pivot. As it does this, the force of the water in the tipper creates a moment that causes the entire tipper to rotate about its pivot and dump all of the water into the reservoir.”
The students designed the tipper/siphon through a UC San Diego mechanical and aerospace engineering class (MAE156)taught by Nathan Delson. In the class, student teams work on real-world design projects, which come for the wide range of enterprises. After 15 weeks of working on a project, the student team delivers a working prototype to the sponsor.
“The purpose of these projects is to expose our students to the rich complexity of real-world challenges where engineering analysis must be used side-by-side with creativity, teamwork, and project management to come up with effective solutions,” said Delson, director of the UC San Diego Mechanical Engineering Design Center. “Whether they are designing the next generation iPhone or an agricultural solution for Africa, we teach our students to apply engineering methods to satisfy user needs. By providing a broad range of student design projects we strengthen our ties to the San Diego community as a whole and prepare our students for a rapidly changing world where design challenges occur in many areas.”
UCSD engineering students helped the ECOLIFE Foundation design a sustainable aquaponics system for local communities in Uganda.
For student Peter Cottle, the ECOLIFE Foundation project gave him a chance to use engineering to make a global impact.
“Engineering and advancements in technology truly have the ability to free people from economic conditions and allow a country to join the developed world,” Cottle said. “We hope that our bell siphon improvements can be implemented in aquaponics systems throughout Africa, eventually allowing these tribes to obtain their protein from home-farmed fish rather than disease-ridden bushmeat. Hopefully ECOLIFE Foundation’s aquaponics systems will help countries to escape the poverty and problems associated with developing countries.”
The ECOLIFE Foundation aquaponics system will be delivered to Uganda this spring.
“The students came through in an amazing way,” said Bill Toone, ECOLIFE Foundation’s executive director. “We wanted to make sure the system can be used simply, reliably and inexpensively. This region of the world has limited resources and little expertise and, like everywhere else, huge cultural traditions that lock people into certain behaviors. We wanted the students to help us mitigate the fluctuating power and amount of water going into the system and have it be reliable.
"With the wave of loss of endangered species that we’re addressing we have to think beyond political borders, and beyond traditional conservation” Toone added. “We share the same atmosphere and resources. What we each do affects everyone. We have toview the world as a complete package now. In the end, it is about all people and our future.”
Jacobs School of Engineering