Henry Wells Lawrence Memorial Lectures, Number 3

Third volume of addresses given as part of a lecture series in honor of Connecticut College Professor of History, Henry Wells Lawrence. Edited by Chester McA. Destler. Contents are as follows: The Reasons for the Failure of the Paris Peace Settlement, Hajo Holborn, Professor of History, Yale University From Individualism to Collectivism in American Land Policy, Paul Wallace Gates, Professor of History, Cornell University Representative Institutions in England and Europe in the Fifteenth Century in Relation to Later Developments, Helen Maud Cam, Professor of History, Radcliffe College, Harvard Universityhttps://digitalcommons.conncoll.edu/ccbooks/1009/thumbnail.jp

Modelling studies of the hazards posed by liquid hydrogen use in civil aviation

As part of the ENABLEH2 project, modelling studies have been carried out to examine liquid hydrogen release and dispersion behaviour for different LH2 aircraft and airport infrastructure leak/spill accident scenarios. The FLACS CFD model has been used to simulate the potential hazard effects following an accidental LH2 leak, including the extent of the flammable LH2 clouds formed, magnitude of explosion overpressures and pool fire radiation hazards. A comparison has also been made between the relative hazard consequences of using LH2 with conventional Jet A/A-1 fuel. The results indicate that in the event of accidental fuel leak/spill LH2 has some safety advantages over Jet A/A-1 but will also introduce additional hazards not found with Jet A/A-1 that will need to be carefully managed and mitigated against.European Union funding: 76924

Reference genome of Lumpfish Cyclopterus lumpus Linnaeus provides evidence of male heterogametic sex determination through the AMH pathway

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The nonlinear dynamics of flashover in compartment fires

The development of a fire within a compartment represents an event of both theoretical and practical interest, displaying a variety of nonlinear behaviour. Of particular importance is the flashover transition, whereby a small fire undergoes a rapid intensification to engulf the whole compartment. In this thesis we examine the influence of the controlling parameters, on the qualitative nonlinear behaviour of three different simplified compartment fire models, by applying some of the techniques of nonlinear dynamics. The variation in response of a nonlinear model, indicated by some representative quantity (e.g. temperature) as a particular distinguished parameter varies, can be traced out to produce a bifurcation diagram. The effect of the remaining auxiliary control parameters can then be mapped out by locating the boundaries or varieties which separate the different qualitative types of bifurcation diagram exhibited by the model. Such varieties are defined in terms of the singularities of the function(s) defining the model, and its derivatives. We show that these definitions can be extended to include the transition points between fuel and ventilation controlled burning exhibited by compartment fire models. Path following techniques are also presented as a means of obtaining bifurcation diagrams and varieties numerically. These techniques are applied to construct parameter maps and classify the possible bifurcation diagram types for three different simplified compartment fire models, incorporating the effect of; radiation feedback from the compartment, vitiation of the compartments oxygen atmosphere and varying combustion efficiency. Based upon this analysis, an index is derived as a means of evaluating the tlashover potential of a given compartment. Finally a comparison of experimental data obtained for two thermoplastic fuels is made, confirming the occurrence of the qualitative nonlinear features predicted theoretically, and in particular the critical nature of the flashover transition

Enabling cryogenic hydrogen-based CO2-free air transport: meeting the demands of zero carbon aviation

Flightpath 2050 from the European Union (EU) sets ambitious targets for reducing the emissions from civil aviation that contribute to climate change. Relative to aircraft in service in year 2000, new aircraft in 2050 are to reduce CO2 emissions by 75% and nitrogen oxide (NOx) emissions by 90% per passenger kilometer flown. While significant improvements in asset management and aircraft and propulsion-system efficiency and are foreseen, it is recognized that the Flightpath 2050 targets will not be met with conventional jet fuel. Furthermore, demands are growing for civil aviation to target zero carbon emissions in line with other transportation sectors rather than relying on offsetting to achieve “net zero.” A more thorough and rapid greening of the industry is seen to be needed to avoid the potential economic and social damage that would follow from constraining air travel. This requires a paradigm shift in propulsion technologies. Two technologies with potential for radical decarbonization are hydrogen and electrification. Hydrogen in some form seems an inevitable solution for a fully sustainable aviation future. It may be used directly as a fuel or combined with carbon from direct air capture of CO2 or other renewable carbon sources, to synthesize drop-in replacement jet fuels for existing aircraft and engines. As a fuel, pure hydrogen can be provided as a compressed gas, but the weight of the storage bottles limits the practical aircraft ranges to just a few times that is achievable with battery power. For longer ranges, the fuel needs to be stored at lower pressures in much lighter tanks in the form of cryogenic liquid hydrogen (LH2)

The use of spatial analytical techniques to explore patterns of fire incidence: A South Wales case study

The application of mapping and spatial analytical techniques to explore geographical patterns of crime incidence is well established. In contrast, the analysis of operational incident data routinely collected by fire brigades has received relatively less research attention, certainly in the UK academic literature. The aim of this paper is to redress this balance through the application of spatial analytical techniques that permit an exploration of the spatial dynamics of fire incidents and their relationships with socio-economic variables. By examining patterns for different fire incident types, including household fires, vehicle fires, secondary fires and malicious false alarms in relation to 2001 Census of Population data for an area of South Wales, we demonstrate the potential of such techniques to reveal spatial patterns that may be worthy of further contextual study. Further research is needed to establish how transferable these findings are to other geographical settings and how replicable the findings are at different geographical scales. The paper concludes by drawing attention to the current gaps in knowledge in analysing trends in fire incidence and proposes an agenda to advance such research using spatial analytical techniques. (c) 2007 Elsevier Ltd. All rights reserved