Ecological Complex Systems

Main aim of this topical issue is to report recent advances in noisy nonequilibrium processes useful to describe the dynamics of ecological systems and to address the mechanisms of spatio-temporal pattern formation in ecology both from the experimental and theoretical points of view. This is in order to understand the dynamical behaviour of ecological complex systems through the interplay between nonlinearity, noise, random and periodic environmental interactions. Discovering the microscopic rules and the local interactions which lead to the emergence of specific global patterns or global dynamical behaviour and the noises role in the nonlinear dynamics is an important, key aspect to understand and then to model ecological complex systems.Comment: 13 pages, Editorial of a topical issue on Ecological Complex System to appear in EPJ B, Vol. 65 (2008

Theoretical and experimental study on explosion safety of hydrocarbons oxidation at elevated conditions: Relevance for safe design and operation of industrial processes

Applied Science

A review of explosion prevention and protection systems suitable as ultimate layer of protection in chemical process installations

Ideally, explosion risk is identified and prevented at an early stage of process design, forming a key part of the inherently safer design (ISD) approach. However, in practice, explosion risk often cannot be eliminated completely. Reliable preventive and protective systems must therefore be applied, as part of the now widely applied barrier or independent layer of protection approach (LOPA) to process design. Doing this requires a comprehensive knowledge of available systems. However, such a comprehensive overview of the various systems does not yet exist. This paper provides such an overview. The commercially available explosion prevention and mitigative systems applicable to gas, dust, mist and hybrid (gas-aerosol) explosions are discussed, including basic principles and proper application for single and combined systems, for confined installations. Limitations of the applicability as well as limitations of the research-base of the various systems are also discussed

Test methods for determining explosion characteristics re-examined

PresentationDetailed knowledge about the explosion indices is essential for safe and efficient operation. For optimal operation, explosion indices should be known under realistic process conditions, in other words under the prevailing temperature, pressure and turbulence levels of the process. The equipment described in this paper allows experiments to be carried out under actual process conditions within the following ranges: initial temperatures up to 400 °C, initial pressures up to 35 bar, oxygen enriched mixtures up to mixtures involving pure oxygen and under known and adjustable turbulence levels. The explosion indices can thus be determined under realistic conditions avoiding any uncertainties in extrapolation from data obtained under ambient conditions. Another major issue is to design proper safety measures. A typical example, involving the safe engineering of processes handling ethylene oxide, is illustrated with some preliminary experimental results