ENGR 482 Lecture 23
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Interesting Websites
Historical engineering practices
- Pyramids in Egypt
- Great Wall of China
- Roman Bridge in Merida, Spain.
c.f. engineering today
- U.S. Strip mall (lifetime of 15 years)
- Cell phones
- Fast, powerful (heavy, gas-guzzlingmuscle cars
E-Waste
70% of overall toxic waste is found in landfills
Lead, Mercury, PVC, etc. can be toxic
- Before plasma and LCD screens, TVs were cathode ray tubes (CRTs)
- About 20% of CRT's are made from lead: 4–8 lbs per unit
- Feb. 19, 2009: FCC requires TVs run a digital signal, resulting in many consumers disposing of their old televisions
- Cell phones are less toxic, but there are more of them:
- 500 M ready to be disposed
- Most hazardous component is the battery (Ni-Cd), but now are Li-ion
Columbite-tantalite (ore of Niobium and Tantalum) makes batteries more efficient, but has driven us to mine in Gorilla populations
Life Cycle Assessment
Recall:
- inventory the resources and energy related to inputs and outputs
- Evaluate potential environmental impacts
- Interpret results
Tool of evaluation, but not the end-all
Used to
- identify improvement opportunities
- make decisions
- marketing opportunities (Eco-labels)
Some Effects considered in assessments:
- Climate Change
- Acidification (acid rain)
- Smog
- Human Toxicity
- Ecotoxicity
- Eutrophication
- Ozone Layer depletion
- Radioactive releases
Functional Unit
A measure of the function of the studied system
Example for paint system: unit surface area protected for 10 years.