OHL assessment and risk evaluation based on environmental and inspection data

Abstract

a b s t r a c tTo reveal potential impacts to environment and human health quantitatively, co-composting and utilization of sludge and woodchips were investigated using a life-cycle-based model, EASETECH. Three scenarios were assessed through experiments using different material ratios. Emission amounts during cocomposting were determined by monitoring data and mass balance. With 100 t sludge treatment, cocomposting showed impacts to acidification (29.9 PE) and terrestrial eutrophication (57.7 PE) mainly for ammonia emission. Compost utilization presented savings on freshwater eutrophication (À1.5 PE) because of phosphorus substitution. With the application of fewer woodchips, impacts to acidification and terrestrial eutrophication decreased because more ammonium was reserved rather than released. All impacts to human toxicity were not significant (8.2 ± 0.6 PE) because the compost was used for urban landscaping rather than farming. Trace gaseous compounds showed marginal impacts to global warming and toxicity categories. The results provide a new perspective and offer evidence for appropriate sludge treatment selection.

Modelling weather dependence in online reliability assessment of power systems

“…Existing studies by the Portuguese TSO apply threat-based failure rate models to their system. 25,26 Notably, the set of threats considered by the Portuguese system is quite different from those experienced in Iceland. 27 There are few published studies on threat probabilities to real-world power systems, owing both to security concerns and the fact that there was, historically, no need for probabilistic models, since the deterministic N - 1 criterion was previously sufficient for power system reliability.…”