Sufficient Scope in Current Aircraft Technology Developments?

Air travel demand is growing worldwide with an approximate worldwide long term average of 5 to 6% annually. This growth has both very positive and negative effects. Aviation is deeply embedded in our society. Dramatic decrease in ticket prices has brought to many the possibility of reaching many destinations worldwide in a day’s travel. It is claimed by some that the negative effects – such as noise pollution and greenhouse gas emissions - will not become more problematic in the future, because technologies are being developed that will compensate them. The starting point of this research is to discover whether this claim concerning the potential of current aircraft technology developments is true. In other words: is the current development in aircraft technology capable to contribute to a sustainable development in the aviation sector by keeping current positive effects, while mitigating the negative effects? Existing research on this issue is mostly trend research, focussing at the average technology efficiency increase and extrapolating this to the future. In a context where multiple actors have to decide about what to do, this extrapolation is not enough. An aggregated number does not reveal the concrete options and causal relations behind it. This paper, therefore, introduces the open and explicit method of systems analysis to answer the question if (and if so, how) new aircraft technology can mitigate the adverse effects of an increasing air travel demand, while keeping the benefits. It presents analytical results in terms of numbers and score cards in order to feed the policy process that eventually should lead to policy in order to solve the problem. In light of the results of the systems analysis, this paper concludes that current developments in aircraft technology are not sufficient to mitigate the adverse effects of growth. Our research suggests that the combination of the efficiency improvement rate, the growth rate of the demand for air travel, and the long replacement times for older technology do in fact not cancel each other out. In order to achieve a sustainable development in the aviation sector, this systems analysis approach shows the limited (though important) influence technology can have on the full concept of sustainable development. We suggest to not only invest more into developing ever better technologies, but to also search for non-technical solutions in order to address the full concept of sustainable development

Special Editorial Issue EJTIR

Globalisation and economic growth have led to aviation’s deep incorporation into our society. People and goods can be transported almost anywhere on the globe in a relatively short time and at relatively low prices. The rate of growth in air traffic demand has for decades been higher than that of the world economy. As world population increases, economic growth and ongoing globalisation are expected to continue fuelling air traffic’s explosive growth (Walker et al, 2008). As a result the large aircraft manufacturers in the world, Airbus and Boeing, specify in their market forecast annual growth percentages of around 5 to 6%. Since late 2008, the economic crisis has significantly reduced the demand for aviation (IATA, 2008; 2009). However, most authors consider this slowdown to be but temporary. In many occasions in the past, aviation demand growth curbed but growth figures always relatively quickly recovered picking up the growth lines followed before the crisis. The latest occasion has been the recovery in 2004 from the period of stagnation following the attacks on the World Trade Centre in New York City in 2001. In the majority of designed future scenarios for air traffic, the increasing demand for air traffic is expected to continue. This continuing growth will have some valuable effects, but also some drawbacks

Measurement of Z0 decays to hadrons, and a precise determination of the number of neutrino species

We have made a precise measurement of the cross section for e+e--->Z0-->hadrons with the L3 detector at LEP, covering the range from 88.28 to 95.04 GeV. From a fit to the Z0 mass, total width, and the hadronic cross section to be MZ0=91.160 +/- 0.024 (experiment) +/-0.030(LEP) GeV, [Gamma]Z0=2.539+/-0.054 GeV, and [sigma]h(MZ0)=29.5+/-0.7 nb. We also used the fit to the Z0 peak cross section and the width todetermine [Gamma]invisible=0.548+/-0.029 GeV, which corresponds to 3.29+/-0.17 species of light neutrinos. The possibility of four or more neutrino flavors is thus ruled out at the 4[sigma] confidence level.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28683/3/0000500.pd

Mapping genomic loci implicates genes and synaptic biology in schizophrenia

Schizophrenia has a heritability of 60-80%1, much of which is attributable to common risk alleles. Here, in a two-stage genome-wide association study of up to 76,755 individuals with schizophrenia and 243,649 control individuals, we report common variant associations at 287 distinct genomic loci. Associations were concentrated in genes that are expressed in excitatory and inhibitory neurons of the central nervous system, but not in other tissues or cell types. Using fine-mapping and functional genomic data, we identify 120 genes (106 protein-coding) that are likely to underpin associations at some of these loci, including 16 genes with credible causal non-synonymous or untranslated region variation. We also implicate fundamental processes related to neuronal function, including synaptic organization, differentiation and transmission. Fine-mapped candidates were enriched for genes associated with rare disruptive coding variants in people with schizophrenia, including the glutamate receptor subunit GRIN2A and transcription factor SP4, and were also enriched for genes implicated by such variants in neurodevelopmental disorders. We identify biological processes relevant to schizophrenia pathophysiology; show convergence of common and rare variant associations in schizophrenia and neurodevelopmental disorders; and provide a resource of prioritized genes and variants to advance mechanistic studies. © 2022. The Author(s), under exclusive licence to Springer Nature Limited