Hydrodynamic Irreversibility in Particle Suspensions with Non-Uniform Strain

A dynamical phase transition from reversible to irreversible behavior occurs when particle suspensions are subjected to uniform oscillatory shear, even in the Stokes flow limit. We consider a more general situation with non-uniform strain (e.g. oscillatory channel flow), which is observed to exhibit markedly different dynamics. Self-organization and shear-induced migration only partially explain the delayed, simultaneous onset of irreversibility across the channel. The onset of irreversibility is accompanied by long-range correlated particle motion. This motion leads to particle activity even at the channel center, where the strain is negligible, and prevents the system from evolving into a reversible state

APPLICATION OF TUNED LIQUID DAMPERS TO MITIGATE WIND- INDUCED TORSIONAL MOTION

The tuned liquid damper (TLD) is a proven and an increasingly popular auxiliary device for mitigating the dynamic effects induced by wind loading on tall buildings. During a dynamic loading event, the water inside a TLD will slosh against the end walls of the tank, thereby imparting a force approximately anti-phase to the motion of the building. The current study uses a multi-modal TLD system to reduce the resonant torsional responses of a real high-rise building. The building is sensitive to torsion in the first two vibration modes; therefore, a unique TLD system is designed to damp these two modes by displacing the tanks away from the center of mass of the building. The TLD system is capable of reducing the serviceability responses to an acceptable level. In addition, the current study demonstrates the possible reduction in wind loading experienced by the building. The reduced wind loading leads to a 16.9% reduction in the cost of steel reinforcement in the concrete shear walls. Furthermore, the robustness of the TLD system is evaluated and practical TLD design issues are discussed

APPLICATION OF TUNED LIQUID DAMPERS TO MITIGATE WIND- INDUCED TORSIONAL MOTION

The tuned liquid damper (TLD) is a proven and an increasingly popular auxiliary device for mitigating the dynamic effects induced by wind loading on tall buildings. During a dynamic loading event, the water inside a TLD will slosh against the end walls of the tank, thereby imparting a force approximately anti-phase to the motion of the building. The current study uses a multi-modal TLD system to reduce the resonant torsionalresponsesofarealhigh-risebuilding. Thebuildingissensitivetotorsioninthe first two vibration modes; therefore, a unique TLD system is designed to damp these two modes by displacing the tanks away from the center o f mass o f the building. The TLD system is capable of reducing the serviceability responses to an acceptable level. In addition, the current study demonstrates the possible reduction in wind loading experienced by the building. The reduced wind loading leads to a 16.9% reduction in the cost of steel reinforcement in the concrete shear walls. Furthermore,the robustness of the TLD system is evaluated and practical TLD design issues are discussed

Emotional experiences beyond the classroom: Interactions with the social world

Research into the emotional experiences of language learners and their impact upon the language-learning process remains relatively undernourished within second language education. The research available focuses primarily on emotions experienced within the classroom, rather than in the daily lives of learners within various social contexts. This article contends that the focus placed upon emotions within the relatively structured environment of the formal classroom is problematic, particularly within an ESL environment, as the target language is more frequently experienced beyond the classroom. Drawing on data collected within Australia, the study explored the emotional experiences of a small cohort of eight university-level ESL learners experienced within their various social interactions beyond the classroom with a specific focus on the emotions of hope, enjoyment and frustration. Semi-structured interviews revealed that their emotional experiences beyond the classroom were particularly intense in comparison to emotional experiences within the formal language-learning classroom

Earwigs (Dermaptera) from the Mesozoic of England and Australia, described from isolated tegmina, including the first species to be named from the Triassic

Dermaptera (earwigs) are described from the Triassic of Australia and England, and from the Jurassic and Cretaceous of England. Phanerogramma heeri (Giebel) is transferred from Coleoptera and it and Brevicula gradus Whalley are re-described. Seven new taxa are named based on tegmina: Phanerogramma australis sp. nov. and P. dunstani sp. nov. from the Late Triassic of Australia; P. gouldsbroughi sp. nov. from the Triassic/Jurassic of England; Brevicula maculata sp. nov. and Trivenapteron moorei gen. et sp. nov. from the Early Jurassic of England; and Dimapteron corami gen et sp. nov. and Valdopteron woodi gen. et sp. nov. from the Early Cretaceous of England. Phanerogramma, Dimapteron and Valdopteron are tentatively placed in the family Dermapteridae, and Trivenapteron is incertae sedis. Most of the specimens of Phanerogramma heeri are from the Brodie Collection and labelled ‘Lower Lias'; however, some were collected from the underlying Penarth Group, thus this species spans the Triassic/Jurassic boundary. The palaeobiogeography of the Late Triassic and Early Jurassic of England is discussed

Approaching the adiabatic timescale with machine-learning

The control and manipulation of quantum systems without excitation is challenging, due to the complexities in fully modeling such systems accurately and the difficulties in controlling these inherently fragile systems experimentally. For example, while protocols to decompress Bose-Einstein condensates (BEC) faster than the adiabatic timescale (without excitation or loss) have been well developed theoretically, experimental implementations of these protocols have yet to reach speeds faster than the adiabatic timescale. In this work, we experimentally demonstrate an alternative approach based on a machine learning algorithm which makes progress towards this goal. The algorithm is given control of the coupled decompression and transport of a metastable helium condensate, with its performance determined after each experimental iteration by measuring the excitations of the resultant BEC. After each iteration the algorithm adjusts its internal model of the system to create an improved control output for the next iteration. Given sufficient control over the decompression, the algorithm converges to a novel solution that sets the current speed record in relation to the adiabatic timescale, beating out other experimental realizations based on theoretical approaches. This method presents a feasible approach for implementing fast state preparations or transformations in other quantum systems, without requiring a solution to a theoretical model of the system. Implications for fundamental physics and cooling are discussed.Comment: 7 pages main text, 2 pages supporting informatio

Incorporating habitat distribution in wildlife disease models: conservation implications for the threat of squirrelpox on the Isle of Arran

Emerging infectious diseases are a substantial threat to native populations. The spread of disease through naive native populations will depend on both demographic and disease parameters, as well as on habitat suitability and connectivity. Using the potential spread of squirrelpox virus (SQPV) on the Isle of Arran as a case study, we develop mathematical models to examine the impact of an emerging disease on a population in a complex landscape of different habitat types. Furthermore, by considering a range of disease parameters, we infer more generally how complex landscapes interact with disease characteristics to determine the spread and persistence of disease. Specific findings indicate that a SQPV outbreak on Arran is likely to be short lived and localized to the point of introduction allowing recovery of red squirrels to pre-infection densities; this has important consequences for the conservation of red squirrels. More generally, we find that the extent of disease spread is dependent on the rare passage of infection through poor quality corridors connecting good quality habitats. Acute, highly transmissible infectious diseases are predicted to spread rapidly causing high mortality. Nonetheless, the disease typically fades out following local epidemics and is not supported in the long term. A chronic infectious disease is predicted to spread more slowly but can remain endemic in the population. This allows the disease to spread more extensively in the long term as it increases the chance of spread between poorly connected populations. Our results highlight how a detailed understanding of landscape connectivity is crucial when considering conservation strategies to protect native species from disease threats