Page 237 - Materials Chemistry, Second Edition

L1644_C05.fm Page 210 Monday, October 20, 2003 12:02 PM

8. What are the general strategies for the assessment of uncertainties in LCA
studies?
9. List the main steps of an MC simulation.
10. Explain the relative importance of the different parameters for the final
result when estimated by MC simulation.
11. In the framework of uncertainty assessment in IPA, a large amount of
damage function data is compiled. Why can’t all of them be considered?
Give an explanation.
12. In an assessment study by MC simulation, data uncertainties appear as a
percentage of the standard deviation, and a log-normal distribution is used.
Discuss the suitability of this choice.
13. Explain the main sources of uncertainties in IPA and LCI, respectively.
14. What is the importance of determining the probability distributions of
ERA data? Describe which kind of probability distribution can be asso-
ciated with the following events:
• The results of a weight study for a group of people: 155.6 lb; 141.7
lb; 158.6 lb; 174.2 lb; 172.1 lb; 164 lb; 168.9 lb; 139.2 lb; 147 lb;
156.2 lb; 171.7 lb
• The concentrations in ppm of a toxin in samples taken at different
points of a river: 0.123; 0.095; 0.154; 0.298; 0.365; 0.612; 0.389;
0.474; 0.299; 0.494; 0.341; 0.612; 0.511; 0.744; 0.519; 0.654; 0.476;
0.437; 0.365; 0.26; 0.166; 0.198; 0.108; 0.165
• The results of a study about relative abundance (%) of endangered
species in an ecosystem: 43; 26; 12.1; 7.4; 3.6; 2.5; 1.4; 1.2; 1; 0.6;
0.3; 0.2; 0.1; 0.08; 0.07; 0.06; 0.05; 0.04
Do any of these distributions correspond to normal distribution and to log-
normal?
15. Using the example of the LCA of a chair given in Chapter 2:
• Assuming experimental data related to inputs and wastes of a similar
process in Europe, discuss the probability distributions of the param-
eters considered in an eventual study in your country.
• Identify the possible uncertainties and variability if an MC simulation
is performed.

REFERENCES

Arija, V., Salas, J., Fernández-Ballart, J., Cucó, G., Martí-Henneberg, C. (1996), Consumo,
hábitos alimentarios y estado nutricional de la población de Reus (IX). Evolución
del consumo de alimentos, de su participación en la ingestión de energía y nutrientes
y de su relación con el nivel socioeconómico y cultural entre 1983 y 1993, Med.
Clinica, 106, 174–179.
Decisioneering (1996), Crystal Ball Version 4.0 — Guide de l’utilisateur, Editions MEV,
Versailles, France.
EC (European Commission) (1995), ExternE — Externalities of Energy, 6 vols.,
EUR 16520–162525. DG XII Science, Research and Development, Brussels.

© 2004 CRC Press LLC