Improving Feasibility of Point to Point Operations Through Civil Aerial Refuelling

Re-imagining of the aerial transportation system has become increasingly important as the need for significant environmental and economic efficiency gains has become ever more prevalent. A number of studies have highlighted the benefits of the adoption of air to air refuelling within civil aviation. However, it also opens up the potential for increased flexibility in operations through smaller aircraft, shifting emphasis away from the traditional hub and spoke method of operation towards the more flexible Point to Point operations. It is proposed here that one technology can act as an enabler for the other, realising benefits that neither can realise as a standalone. The impact of an air-toair refuelling enabled point to point system is discussed, and the affect on economic and environmental cost metrics relative to traditional operations evaluated. An idealised airport configuration study shows the difference in fuel burn for point to point networks to vary from -23% to 28% from that of Hub and Spoke depending on the configuration. The sensitive natures of the concepts are further explored in a second study based on real airport configurations. The complex effect of the choice of a Point to Point or Hub and Spoke system on fuel burn, operating cost and revenue potential is highlighted. Fuel burn savings of 15% can be experienced with AAR over traditional refuelling operations, with point to point networks increasing the available seat miles (by approximately 20%) without a proportional increase in operating cost or fuel.

Chapter Three – Host–Parasite Interactions and the Evolution of Immune Defense

Parasites and pathogens are ubiquitous and act as an important selection pressure on animals. Here, drawing primarily on our own research, mostly on insects, we illustrate how host-parasite interactions have played a role in the evolution of a range of phenomena, including animal coloration, social behavior, foraging ecology, sexual selection, and life-history tradeoffs, as well as how variation in host behavior and ecology can drive variation in parasitism risk and host allocation of resources to immunity and other antiparasite defenses. We conclude by identifying key areas for future study.

Reforming civil engineering studies in recession times

The recent global economic and financial crisis has led the economies of many countries into recession, in particular at the periphery of the European Union. These countries currently face a significant contraction of both public investment in infrastructure and private investment in buildings and, as a result, the unemployment is particularly noticeable in the civil engineering and building sectors. Consequently, in all countries in recession the professional development of fresh civil engineering graduates is disproportionate to their high study effort and qualifications, since they rarely have the opportunity to gain experience in practice and their knowledge gradually becomes obsolete. Under these circumstances, it is imperative for the technical universities in countries in recession to plan and implement a substantial reform of the civil engineering studies syllabus. The objective should be to enable graduates to broaden the scope of their professional activity and increase their employability. In this paper, the widening of civil engineering studies curricula is proposed, in particular in the light of the development of the graduates’ potential on project, programme and portfolio management. In this direction, after a thorough literature review, including ASCE's Body of Knowledge for the 21st century and IPMA's Competence Baseline, it is recommended among others: to increase significantly the offered modules on project management and add new modules on strategy management, leadership behavior, delivery management, organization and environment etc; to provide adequate professional training during the university studies five year period; and to promote fresh graduates’ certification by professional bodies. The proposals are exemplified by presenting a reformed syllabus for the civil engineering studies offered currently by the National Technical University of Athens.