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in sustainability, appropriate technology and poverty reduction.
your site to find, co-create and improve the solutions we need. Our vision and mission.
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As part of the Emergency Sanitation Project, the International Federation of Red Cross and Red Crescent Societies announce a student emergency sanitation design project. Deadline 3 March 2014 |
What does an LED traffic light look like? An LED traffic light looks very similar to a regular traffic light. It still gets the job done and is actually brighter. An LED is actually very small and therefore the traffic light is made up of a bunch of smaller lights, this is apparent when you look closely. The color of the light depends on the exact composition inside the bulb.
Who Invented the LED? It all began when Oleg Vladimirovich created the first LED in 1927. There was no practical use for it until 1962 when it was discovered that the infrared LED could be changed into a visible red LED.
How does an LED work? An LED is basically a tiny light bulb with a semiconductor diode in place of a filament. Inside the diode, there are positively and negatively charged areas. When a voltage is applied to the diode with the positive end hooked up to the negative area and the negative end hooked up to the positive area the electrons inside become excited and jump from the positively charged to negatively charged areas. This interaction produces light.
What is a diode? A diode is a component that restricts the directional flow of charge carriers. Also a diode allows an electric current to flow in one direction, but blocks it in the opposite direction.
Recent winners of the $25,000 Economic Fuel award. Wild Chick Farm pecks ahead on local sustainable chicken raising.
The water leaving our homes carries nutrients and value. It may also contain pathogens, and/or harsh chemicals and care should be taken with it. However, it is not a great risk compared to blackwater (sewage). Redirecting the water we use for tasks such as showering allows us to reclaim some of that value to grow plants and recharge the water table. It may be necessary to choose our soaps and detergents more carefully, if we use the greywater for watering and fertilizing plants. |
Queen's Applied Sustainability Research Group completed projects and publications: This category lists completed projects for the Category:Queens Applied Sustainability Group. Following the individual links leads to a summary of the project and key findings, related Category:Queens Applied Sustainability Group Literature Reviews, Category:Queens Applied Sustainability Group Lab Protocols , and an open access version of the paper published in a peer reviewed journal.
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- FREE Chaps of Open-Source Lab: How to Build Your Own Hardware and Reduce Research Costs
- Recycle waste plastic into valuable products at home
- Students Build a School from Waste Products in the Dominican Republic
- Salt: Clears Muddy Water for Solar Water Disinfection
- Open access to The Case for Open Source Appropriate Technology
- Occupy Sustainability
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[×] Medical devices
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