TRENDS AND SIMILARITIES IN C1-C4 PRIMARY ALCOHOL HIGH-TEMPERATURE IGNITION

Abstract A review of shock tube ignition of primary alcohols from methanol to n-butanol is presented. Most of these literature data were obtained in studies of individual alcohols. Recent work published by the current authors focused on the comparative study of these alcohols, showing similarity in their ignition behavior. This similarity is also observed when ignition delays obtained by other groups under the same conditions are compared. Further comparison is carried out using ignition correlations obtained in the previous study by the current authors. A similar approach in the study of flame propagation of methanol, ethanol and n-butanol was reported by Veloo et al. [Veloo et al., Combust. Flame, 157 (2010) 1989-2004, concluding that under lean conditions the flames of these alcohols propagate with the same velocity. The same trend was observed under rich conditions, apart from methanol flames which were found to propagate faster. However, the comparable behavior is not fully captured by the various literature mechanisms of these fuels. The observed similarity, which is not obvious from the analysis of individual alcohols, can be employed in the development, validation and optimization of their detailed and reduced chemical kinetic models. Furthermore, this similarity can be useful in the practical design and modification of engine systems for flexible alcohol-based fuels

Tracing the origins of rescued chimpanzees reveals widespread chimpanzee hunting in Cameroon

<p>Abstract</p> <p>Background</p> <p>While wild chimpanzees are experiencing drastic population declines, their numbers at African rescue and rehabilitation projects are growing rapidly. Chimpanzees follow complex routes to these refuges; and their geographic origins are often unclear. Identifying areas where hunting occurs can help law enforcement authorities focus scarce resources for wildlife protection planning. Efficiently focusing these resources is particularly important in Cameroon because this country is a key transportation waypoint for international wildlife crime syndicates. Furthermore, Cameroon is home to two chimpanzee subspecies, which makes ascertaining the origins of these chimpanzees important for reintroduction planning and for scientific investigations involving these chimpanzees.</p> <p>Results</p> <p>We estimated geographic origins of 46 chimpanzees from the Limbe Wildlife Centre (LWC) in Cameroon. Using Bayesian approximation methods, we determined their origins using mtDNA sequences and microsatellite (STRP) genotypes compared to a spatial map of georeferenced chimpanzee samples from 10 locations spanning Cameroon and Nigeria. The LWC chimpanzees come from multiple regions of Cameroon or forested areas straddling the Cameroon-Nigeria border. The LWC chimpanzees were partitioned further as originating from one of three biogeographically important zones occurring in Cameroon, but we were unable to refine these origin estimates to more specific areas within these three zones.</p> <p>Conclusions</p> <p>Our findings suggest that chimpanzee hunting is widespread across Cameroon. Live animal smuggling appears to occur locally within Cameroon, despite the existence of local wildlife cartels that operate internationally. This pattern varies from the illegal wildlife trade patterns observed in other commercially valuable species, such as elephants, where specific populations are targeted for exploitation. A broader sample of rescued chimpanzees compared against a more comprehensive grid of georeferenced samples may reveal 'hotspots' of chimpanzee hunting and live animal transport routes in Cameroon. These results illustrate also that clarifying the origins of refuge chimpanzees is an important tool for designing reintroduction programs. Finally, chimpanzees at refuges are frequently used in scientific investigations, such as studies investigating the history of zoonotic diseases. Our results provide important new information for interpreting these studies within a precise geographical framework.</p