These labels range from dye molecules to nanomaterials. We also discuss the general design of signal-transduction mechanisms. (C) 2013 Elsevier Ltd. All rights reserved.”
“Life cycle assessment (LCA) is a popular tool

used to evaluate the environmental performance of municipal solid waste (MSW) management systems. Although reviews of LCAs of MSW have been undertaken to assess the validity of the ‘waste hierarchy,’ a recent review of the goal, scope and results of LCAs of mixed-material MSW management systems has yet to be performed. This paper is a comparative analysis of 20 process-based LCAs of MSW published between 2002 and 2008 in a total of 11 English-language peer-reviewed journals. It quantifies the methodological transparency of the studies and the frequency BTSA1 of use of particular system boundaries, types of data sources, environmental impact categories, impact weightings, economic valuations, sensitivity analyses, and LCA computer models. Net energy use (NEU). global warming potential (GWP), and acidification potential (AP) values for various types of MSW management systems are also compared using statistical indicators.

The reviewed LCAs differ substantially

in their system boundaries. Half or more of the LCAs either do not mention or are unclear in whether or not life cycle emissions from energy inputs or capital equipment are included in the calculation of results. Only four impact categories are common to more than half of the reviewed LCAs. The human and Fer-1 in vitro ecological toxicity Pevonedistat datasheet impact categories are much less common than global warming potential, acidification, and eutrophication.

A financial life cycle costing is present in eight of the reviewed LCAs, while an economic valuation of the environmental impacts is observed in five. Explicit sensitivity analyses are present in 4/20 of the studies, although many more LCAs evaluate the effects of varying model parameters by increasing the number of waste management scenarios. There is no consensus on whether or not to use the marginal or average source of electricity in

calculating environmental impacts. Eight out of the 20 do not mention this source while the remaining LCAs are evenly split between the marginal and average electricity source. One quarter of the reviewed LCAs supply weighted results for the overall environmental performance of MSW management scenarios. All but one of these concurred with the ‘hierarchy of waste’ that the environmental performance of landfilling is lower than that of all the other treatment methods, and that thermal treatments are inferior to recycling.

The comparative analyses of the NEU, GWP and AP results are based on 37, 45, and 42 MSW management scenarios, respectively. As measures of statistical dispersion, the interquartile ranges of the NEU. GWP and AP values are lowest for the landfilling (AP, NEU) and thermal treatment (GWP) scenarios.