Impact resistance of current design composite fan blades tested under short-haul operating conditions

Boron/epoxy and graphite/epoxy composite blades were impacted in a rotating whirligig facility with conditions closely simulating those which might be experienced by a STOL engine impacted with various foreign objects. The tip speed of the rotating blades was 800 feet per second. The blades were impacted with simulated birds, real birds, ice balls, and gravel. The results of composite blade impact tests were compared with a titanium blade tested under similar conditions. Neither composite material indicated a clear superiority over the other. Blades made from both composite materials showed more damage than the titanium blades

Feedbacks on Tune and Chromaticity

Feedbacks on tune, coupling and chromaticity are becoming an integral part of safe and reliable accelerator operation. Tight tolerances on beam parameters typically constrain the allowed oscillation amplitudes to the micrometre range, leaving only a small margin for the transverse beam and momentum excitations required for tune and chromaticity measurements. This contribution presents an overview of these beam-based feedback systems, their architecture and design choices involved. It discusses performance limitations due to cross constraints, non-linearities, the coupling between multiple nested loops, and the interdependence of beam parameters

Real-timefeedback on beam parameters

Traditionally, tight beam parameter stability requirements were most pronounced for light sources and lepton colliders but have now become increasingly important for present and future hadron accelerator operation, not only for performance but also for reasons of machine protection, as recent improvements have led to significantly increased stored beam energies. In the latest generation machines, performance depends critically on the stability of the beam. In order to counteract disturbances due to magnetic imperfections, misalignments, ground motion, temperature changes and other dynamic effects, fully automated control of the key beam parameters â orbit, tune, coupling, chromaticity and energy â becomes an increasingly important aspect of accelerator operation. This contribution presents an overview of beam-based feedback systems, their architecture, performance limitations and design choices involved

Knowledge-based best of breed approach for automated detection of clinical events based on German free text digital hospital discharge letters

OBJECTIVES: The secondary use of medical data contained in electronic medical records, such as hospital discharge letters, is a valuable resource for the improvement of clinical care (e.g. in terms of medication safety) or for research purposes. However, the automated processing and analysis of medical free text still poses a huge challenge to available natural language processing (NLP) systems. The aim of this study was to implement a knowledge-based best of breed approach, combining a terminology server with integrated ontology, a NLP pipeline and a rules engine. METHODS: We tested the performance of this approach in a use case. The clinical event of interest was the particular drug-disease interaction "proton-pump inhibitor [PPI] use and osteoporosis". Cases were to be identified based on free text digital discharge letters as source of information. Automated detection was validated against a gold standard. RESULTS: Precision of recognition of osteoporosis was 94.19%, and recall was 97.45%. PPIs were detected with 100% precision and 97.97% recall. The F-score for the detection of the given drug-disease-interaction was 96,13%. CONCLUSION: We could show that our approach of combining a NLP pipeline, a terminology server, and a rules engine for the purpose of automated detection of clinical events such as drug-disease interactions from free text digital hospital discharge letters was effective. There is huge potential for the implementation in clinical and research contexts, as this approach enables analyses of very high numbers of medical free text documents within a short time period

LHC Beam Stability and Feedback Control - Orbit and Energy -

This report presents the stability and control of the Large Hadron Collider's (LHC) two beam orbits and their particle momenta using beam-based feedback systems. The LHC, presently being built at CERN, will store, accelerate and provide particle collisions with a maximum particle momentum of 7TeV/c and a nominal luminosity of L = 10^34 cm^â2s^â1. The presence of two beams, with both high intensity as well as high particle energies, requires excellent control of particle losses inside a superconducting environment, which will be provided by the LHC Cleaning and Machine Protection System. The performance and function of this and other systems depends critically on the stability of the beam and may eventually limit the LHC performance. Environmental and accelerator-inherent sources as well as failure of magnets and their power converters may perturb and reduce beam stability and may consequently lead to an increase of particle loss inside the cryogenic mass. In order to counteract these disturbances, control of the key beam parameters â orbit, tune, energy, coupling and chromaticity â will be an integral part of LHC operation. Since manual correction of these parameters may reach its limit with respect to required precision and expected time-scales, the LHC is the first proton collider that requires automatic feedback control systems for safe and reliable machine operation. The aim of this report is to help and contribute towards these efforts

Rethinking learning and teaching using plurilingual pedagogy in the UAE: Challenges and success stories

In this chapter, the author reflects on her own process of learning and rethinking plurilingualism and plurilingual education as an expatriate educator in the United Arab Emirates (UAE). She focuses on the concept of translanguaging, which has been introduced, adopted, and employed in curricula in countries that use a plurilingual approach with minority students speaking their home languages, such as the USA and Canada. In the case of the Arabian Peninsula, a closer look at students’ language acquisition and development reveals that the use of teaching subjects in English undermines the role of the native language, Arabic, in their language acquisition process. Therefore, in this concluding chapter, the author offers an insight into her own classroom, letting students’ voices be heard while speaking about their experiences and learning journeys in a translanguaging classroom. She also describes her own perspective as an educator at a higher education institution in the Arabian Peninsula who has successfully implemented a plurilingual pedagogy despite her very basic knowledge of Arabic. As the author points out, based on the feedback she received from her students, her teaching practice led to the linguistic empowerment of her students through bilingualism

Study of the costs and benefits of composite materials in advanced turbofan engines

Composite component designs were developed for a number of applicable engine parts and functions. The cost and weight of each detail component was determined and its effect on the total engine cost to the aircraft manufacturer was ascertained. The economic benefits of engine or nacelle composite or eutectic turbine alloy substitutions was then calculated. Two time periods of engine certification were considered for this investigation, namely 1979 and 1985. Two methods of applying composites to these engines were employed. The first method just considered replacing an existing metal part with a composite part with no other change to the engine. The other method involved major engine redesign so that more efficient composite designs could be employed. Utilization of polymeric composites wherever payoffs were available indicated that a total improvement in Direct Operating Cost (DOC) of 2.82 to 4.64 percent, depending on the engine considered, could be attained. In addition, the percent fuel saving ranged from 1.91 to 3.53 percent. The advantages of using advanced materials in the turbine are more difficult to quantify but could go as high as an improvement in DOC of 2.33 percent and a fuel savings of 2.62 percent. Typically, based on a fleet of one hundred aircraft, a percent savings in DOC represents a savings of four million dollars per year and a percent of fuel savings equals 23,000 cu m (7,000,000 gallons) per year