An Efficient Sliding Mesh Interface Method for High-Order Discontinuous Galerkin Schemes

Sliding meshes are a powerful method to treat deformed domains in computational fluid dynamics, where different parts of the domain are in relative motion. In this paper, we present an efficient implementation of a sliding mesh method into a discontinuous Galerkin compressible Navier-Stokes solver and its application to a large eddy simulation of a 1-1/2 stage turbine. The method is based on the mortar method and is high-order accurate. It can handle three-dimensional sliding mesh interfaces with various interface shapes. For plane interfaces, which are the most common case, conservativity and free-stream preservation are ensured. We put an emphasis on efficient parallel implementation. Our implementation generates little computational and storage overhead. Inter-node communication via MPI in a dynamically changing mesh topology is reduced to a bare minimum by ensuring a priori information about communication partners and data sorting. We provide performance and scaling results showing the capability of the implementation strategy. Apart from analytical validation computations and convergence results, we present a wall-resolved implicit LES of the 1-1/2 stage Aachen turbine test case as a large scale practical application example

Isotopic and zooarchaeological approaches towards understanding aquatic resource use in human economies and animal management in the prehistoric Scottish North Atlantic Islands

Despite being surrounded by aquatic resources, the Prehistoric populations of the North Atlantic Islands have a complex history of aquatic resource that until now has been little understood. Specifically the changing importance and uses of aquatic resources through time, and the role of aquatic resources in the management of animals in prehistory requires further attention. This paper presents results of faunal isotopic analysis in combination with existing human isotopic evidence and zooarchaeological datasets from Neolithic, Bronze Age and Iron Age sites in the Western Isles (also known as the Outer Hebrides) and Orkney to explore the importance of aquatic resources in the lives of these prehistory populations. In Orkney coastal grazing was an important aspect in the management of sheep throughout prehistory, whereas in the Western Isles this was only evident in the Bronze Age. Aquatic protein was also used in the management of pigs in the Western Isles during the Middle Iron Age. There is little evidence of humans consuming aquatic resources in the Neolithic, and only minor evidence of consumption in the Bronze Age. During the Iron Age aquatic resources become more important in the diet of humans. The Prehistoric Atlantic Islanders of Scotland had a complex and dynamic relationship with aquatic resources, especially in the role of animal management that changed throughout the course of prehistory.The authorswould like to express thanks to NERC for funding this research (Grant number NE/F021054/1, PI Richard Evershed), and the NERC Life Sciences Mass Spectrometry Facility in East Kilbride (EK158- 03/10) for their financial assistance with the analytical researc

Changing environments during the Middle-Upper Palaeolithic transition in the eastern Cantabrian Region (Spain): direct evidence from stable isotope studies on ungulate bones

Environmental change has been proposed as a factor that contributed to the extinction of the Neanderthals in Europe during MIS3. Currently, the different local environmental conditions experienced at the time when Anatomically Modern Humans (AMH) met Neanderthals are not well known. In the Western Pyrenees, particularly, in the eastern end of the Cantabrian coast of the Iberian Peninsula, extensive evidence of Neanderthal and subsequent AMH activity exists, making it an ideal area in which to explore the palaeoenvironments experienced and resources exploited by both human species during the Middle to Upper Palaeolithic transition. Red deer and horse were analysed using bone collagen stable isotope analysis to reconstruct environmental conditions across the transition. A shift in the ecological niche of horses after the Mousterian demonstrates a change in environment, towards more open vegetation, linked to wider climatic change. In the Mousterian, Aurignacian and Gravettian, high inter-individual nitrogen ranges were observed in both herbivores. This could indicate that these individuals were procured from areas isotopically different in nitrogen. Differences in sulphur values between sites suggest some variability in the hunting locations exploited, reflecting the human use of different parts of the landscape. An alternative and complementary explanation proposed is that there were climatic fluctuations within the time of formation of these archaeological levels, as observed in pollen, marine and ice cores.This research was funded by the European Commission through a Marie Curie Career Integration Grant (FP7- PEOPLE-2012-CIG-322112), by the Spanish Ministry of Economy and Competitiveness (HAR2012-33956 and Ramon y Cajal-2011-00695), the University of Cantabria and Campus International to ABMA. Radiocarbon dating at ORAU was funded by MINECO-HAR2012-33956 project. J.J was supported initially by the FP7- PEOPLE-2012-CIG-322112 and later by a Marie Curie Individual Fellowship (H2020-MSCA-IF-2014-656122). Laboratory work, associated research expenses and isotopic analysis were kindly funded by the Max Planck Society to M.R

Examination of eye movements of dyslexic children

In der vorliegenden Arbeit wurden die Blickbewegungen von 16 legasthenen Kinder und einer altersentsprechenden Kontrollgruppe beim lauten Lesen von Wörtern mit unterschiedlicher Länge und Häufigkeit untersucht. Bei der Untersuchung wurde ein Scanning-Laser-Ophthalmoskop eingesetzt, welches die exakte Registrierung der Augenbewegungen bei gleichzeitiger Minimierung störender Artefakte ermöglicht. Anliegen der Studie war es zu untersuchen, ob sich kognitive Verarbeitungsschwierigkeiten bei der Worterkennung in zentralen Parametern der Augenbewegungen der legasthenen Kinder abbilden . Die Ergebnisse belegen einen hoch signifikanten Worthäufigkeitseffekt für den prozentualen Anteil an Regressionen, die Anzahl der Fixationen und die Fixationsdauer. Darüber hinaus ergaben sich wichtige Hinweise dafür, daß die Regularität der Graphem-Phonem-Zuordnung zu Unterschieden in Blickbewegungsparametern und der Ausprägung des Wortlängen- und Worthäufigkeitseffekts zwischen der Deutschen und der Englischen Schriftsprache führt. Insgesamt sprechen die Ergebnisse gegen die Hypothese, daß die Auffälligkeiten der Augenbewegungen, und somit die Leseschwierigkeiten, der legasthenen Kinder die Folge eines okulomotorischen Defizits darstellen.The study examined the pattern of eye movements of 16 dyslexic and 16 age-matched, nondyslexic, German-speaking children during reading loudly words of different length and frequency. Eye movements were registered using a Scanning Laser Ophthalmoscope (SLO), which allows a high accurate recording and minimizes interfering artifacts. Central point of interest was to investigate, whether difficulties in the cognitive processes of word recognition are reflected in the eye movement pattern of dyslexic children. The results show a highly significant word-frequency effect for central parameters of the analysis, like the percentage of regressions, the number of fixations and the fixation duration. Furthermore, the results indicate that the regularity of the graphem-phonem-correspondence leads to differences in eye movement parameters, and the outcome of the word-frequency and word-length effect between the German and English written language. Overall, the results do not support the hypothesis that the differences between the eye movement patterns of dyslexic and normal reading children are caused by an oculomotor deficit