non-peer-reviewed ; In sub-task 2.2 of the European Union research Programme "CRAHVI", the University of Limerick (ULIM) is to perform simulations of birdstrike against structures representative of the leading edge of a commuter aircraft. The skin of these structures is made from a metal/composite hybrid material (GLARE). The inputs to this task were as follows: • Pre-test report on birdstrike against GLARE (D2.2.4 [1]) • Experimental Strain and Load Results provided by CEAT • Video Sequences of Bird Strike Tests provided by CEAT • Experimental Test Report D5.3.2 [2] In this report the pre-test simulations [1] are compared with the tests carried out at CEAT [2]. From this comparison, attempts are made to improve the behaviour of the models with respect to the experiment. Additionally the model is extended to include details of the loading frame to allow more quantitative comparisons between test and simulation.
non-peer-reviewed ; In sub-task 2.2 of the European Union research Programme "CRAHVI", the University of Limerick (ULIM) is to perform simulations of birdstrike against structures representative of the leading edge of a commuter aircraft. The skin of these structures is made from a metal/composite hybrid material (Glare). The inputs to this task were test results on Glare under different strain rates from UOXF (D1.1.8) [1], a SPH Bird model created by ESI (D1.4.2) [2], and the geometry of the commuter leading edge structure (in the form of an MSC.Patran file) provided by ALA (D2.1.3) [3]. Some limited background data on Glare was also provided by ALA (D1.1.4) [4]. From these inputs, a mesh has been created and used for pre-test simulation of the birdstrike against the commuter leading edge. Preliminary material calibrations of Glare have also been developed based on the limited data available, with unavailable data provided by reasonable estimation.
Collisions between birds and aircraft (birdstrikes) have caused the loss of at least 88 aircraft and 243 lives in world civil aviation. Conservative estimates suggest that more routine damage and delays following birdstrikes cost the industry and its insurers US$1.2–1.5 billion per year. The majority of strikes happen close to airports and most countries have regulations that require airport managers to control the birdstrike risk on their property. Birdstrike prevention has, however, lagged behind other aspects of flight safety in the development and implementation of risk assessment protocols, possibly because of the inherent difficulty in quantifying the variability in the populations and behavior of the various bird species involved. This article presents a technique that uses both national and airport‐specific data to evaluate risk by creating a simple probability‐times–severity matrix. It uses the frequency of strikes reported for different bird species at a given airport over the preceding five years as a measure of strike probability, and the proportion of strikes with each species that result in damage to aircraft, in the national birdstrike database, as a measure of likely severity. Action thresholds for risk levels for particular bird species are then defined, above which the airport should take action to reduce the risk further. The assessment is designed for airports where the reporting and collation of birdstrike events is reasonably consistent over time and where a bird hazard management program of some sort is already in place. This risk assessment is designed to measure risk to the airport as a business rather than risk to the traveling passenger individually. It therefore takes no account of aircraft movement rate in the calculations and is aimed at minimizing the number of damaging incidents rather than concentrating on catastrophic events. Once set up at an airport, the technique is simple to implement for nonexperts, and it allows managers to focus bird control resources on the species causing the greatest risk, hence maximizing the return on investment. This protocol is now being successfully used at major airports in the United Kingdom and elsewhere in the world.
This paper presents the life story of a single small-business owner of immigrant background who wants his companyto grow. His business strategies are analysed both as a part of his own biographical work, and as they wereinfluenced and framed by broader political, economic and social processes. It is shown how his own personalqualities in combination with opportunity structures in the local market provided favourable conditions for hisbreak-in. Breaking out, however, seems to be presented with different types of barriers, such as lack of access tocapital, discrimination, and the fact that new markets may consist of different sorts of network that are in its turnmore difficult for new actors to enter. But even if newcomers often find these barriers difficult for to overcome,individuals are not just passive objects but also have the opportunity to realize their lives according to their own lifeplans.
Damage resulting from an interaction with lightning current in a military naval vessel, especially in a conflict zone and at the time of a conflict, which leads to the incapacitation of vital activities on the ship, is unacceptable. Because many potential conflict zones are in littoral areas, and because of the increase in lightning activity, both now and expected in the years to come, the provision of protection for naval vessels sailing in those waters should be a high priority. The fact that many standards exclude both naval vessels and the littoral area transforms this work into a potential contemporary solution. With the knowledge about the formation of charge layers in the atmosphere, and about the influence such weather phenomena as fog, clouds, and aerosols have on the transport of additional charge particles, it is possible to understand the formation of lightning. A review of the existing thunderstorm prediction models, and finding a way to verify and update the accuracy of such, is equally important at this stage. Merely understanding the root cause of the problem will not be enough to solve the problem, and therefore an extensive evaluation of the available literature, with a special attention to standards, also has to take place. Evaluating risks and finding what was previously accomplished by others, and any stones they have left unturned, can improve the life expectancy of a system or building block when applying and improving the existing technology. Conventional lightning protection measures serve as points of departure to reach the goals of this research. Such issues as positioning, zoning, and proximity to other components more attractive to lightning strikes must not be overlooked since these are equally important. The rolling sphere concept, as described in civil standards, is applied to naval vessels, and serves now as a basic tool within THALES to estimate the risk of lightning, and possible damage and/or interference. Steps taken by other branches of industry in this direction is investigated too. Investigation and a thorough analysis of other protective methods will help to generate the right ideas to tackle the issue and to improve lightning protection of electronics enclosed by composite structures against both direct contact with the lightning current, and the indirect effects of the associated electric and magnetic fields. Diverters are used by the aircraft industry and the possible use to protect radars under a composite non-conducting radome has been investigated experimentally. The constant increase in our dependency on composite panels throughout many branches of industry, including the naval and maritime sectors, make it necessary to quantify and measure all the risks associated with lightning strikes. Evaluating risks, and where necessary fixing them, will guarantee the successful use of this technology. The lack of shielding properties, and the high likelihood of deterioration and damage as a result of a lightning attachment, mean improvements are essential to make the use of complete fiber reinforced polymer (FRP) composite structures completely safe. A novel idea has been presented, and evaluated via modelling and simulation, as well as via experiments, where the shielding properties of thin materials is used in combination with the coupling of the electromagnetic field, as generated by the lightning strike, into cabling. It has been shown that a smart combination of the shielding and coupling aspects can be very beneficial. Another novel concept is the use of pre-loading of ball bearings. This pre-loading results in a continuous conducting path between the rotating and static part, such that no sparks and hence no damage will occur. A patent application has been filed by THALES Nederland.
Alter (2016) elaborates and defends an ambitious argument advanced by Chalmers (2002) against physicalism. As Alter notes, the argument is valid. But I will argue that not all its premises are true. In particular, it is false that all physical truths are purely structural. In denying this, I focus not on the objects of pure physical theory but on the homely, macroscopic objects of our daily lives.
