Sustainability is expressed as meeting present environmental, social, and economic needs without compromising these factors for future generations A practice cannot be said to be 'sustainable for X years/generations.' The use of any span of time disqualifies the activity. Sustainability is for perpetuity.
Sustainability also means greater efficiency in resource use, ultimately giving benefits to economic growth and overcoming poverty, as well as health and quality of life.
Sustainable design and sustainable development are critical factors to sustainable living. Sustainable design encompasses the development of appropriate technology, which is a staple of sustainable living practices. Sustainable development in turn is the use of these technologies in infrastructure. Sustainable architecture (see Green building) and agriculture are the most common examples of this practice.
LED traffic light FAQ
. Here are a number of frequently asked questions concerning retrofitting street lights with LEDs
. For full information see LED
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. In other words, a diode allows an electric current to flow in one direction, but blocks it in the opposite direction.
A very hot (400 °F) parabolic solar cooker. Made from an reclaimed satellite dish using bicycle powered tools.