Particle Image Velocimetry Data Processing On A Gpu Cluster

Paper presented at 2018 Canadian Society of Mechanical Engineers International Congress, 27-30 May 2018.Particle image velocimetry (PIV) data processing is a computationally expensive process. The immense time taken to analyze data can limit the maximum dataset size. Using graphics processing units (GPUs) has been shown to drastically decrease the processing time for PIV image pairs. The open-source PIV data processing software OpenPIV has been ported to run on a GPU to boost speed and efficiency and has outperformed the CPU version of the software. A multipass method is being implemented in OpenPIV to improve both speed and accuracy. The completed algorithm will be tested on an embedder CPU-GPU device, a desktop computer, and the SOSCIP GPU-accelerated supercomputing cluster. Ultimately, OpenPIV will run on a wide variety of computer platforms an enable larger datasets to be collects, leading to better statistics on the resulting velocity fields

GPU-Native Adaptive Mesh Refinement with Application to Lattice Boltzmann Simulations

The Lattice Boltzmann Method (LBM) has garnered significant interest in General-Purpose Graphics Processing Unit (GPGPU) programming for computational fluid dynamics due to its straightforward GPU parallelization and could benefit greatly from Adaptive Mesh Refinement (AMR). AMR can assist in efficiently resolving flows with regions of interest requiring a high degree of resolution. An AMR scheme that could manage a computational mesh entirely on the GPU without intermediate data transfers to/from the host device would provide a substantial speedup to GPU-accelerated solvers, however, implementations commonly employ CPU/hybrid frameworks instead, due to lack of a recursive data structure. A block-based GPU-native algorithm will be presented for AMR in the context of GPGPU programming and implemented in an open-source C++ code. The meshing code is equipped with a Lattice Boltzmann solver for assessing performance. Different AMR approaches and consequences in implementation are considered before careful selection of data structures enabling efficient refinement and coarsening compatible with single instruction multiple data architecture is detailed. Inter-level communication is achieved by tricubic interpolation and standard spatial averaging. Although the present open-source implementation is tailored for LBM simulations, the outlined grid refinement procedure is compatible with solvers for cell-centered block-structured grids. Link to repository: https://github.com/KhodrJ/AGALComment: 30 pages, 16 figure

Therapeutic Challenges Of Multi-Being

This paper emerges from an attempt to shift the locus of understanding human action from the individual to relationship. In doing so we come to see persons as multi-beings, that is, as constituted within multiple relationships from which they emerge with multiple, incoherent, and often conflicting potentials. Therapy, in this context, becomes a collaborative relationship with the aim of transforming the client\u27s broader relational network. In this view, schooling in a singular practice of therapy artificially limits the therapist\u27s potential, and thus the possible outcomes of the client–therapist relationship. Invited, then, is a reflective eclecticism, in which the myriad potentials of both the therapist and client are considered in tandem. This view is illustrated by contrasting three relational conditions in which clients find themselves, each of which invites a different form of self-expression from the therapist

Mechanical properties of flax and hemp yarns designed for the manufacturing of geotextiles. Improvement of the resistance to soil born microorganisms.

Geotextiles are widely used to stabilize river banks from erosion when these ones are restored into vegetal covered areas as mentioned by European regulations. For these applications imported coir (coconut shell fibres) based geotextiles are generally used because coir fibres show a good resistance to soil degradation. In Europe, flax and hemp plants are already grown for textile, building or oil applications. By-products of these industries such as flax tows and short hemp fibres were used to manufacture yarns. The resistance to degradation via the measurement of the mechanical properties of these yarns submitted to enzymatic (cellulase) and microbial attacks (Cellvibrio gandavensis) mimicking soil degradation was evaluated. Large decreases in mechanical properties were observed, even though these ones were still higher than the as received reference coir material. After impregnation by chitosan of the fibres, the tensile properties of the yarns globally remained unchanged after severe attacks. The chitosan acts as a protection against the soil microorganism attacks. As a consequence, flax and hemp by-products could be good candidates for local manufacturing of biodegradable geotextiles

Pseudo-Riemannian geodesic foliations by circles

We investigate under which assumptions an orientable pseudo-Riemannian geodesic foliations by circles is generated by an $S^1$-action. We construct examples showing that, contrary to the Riemannian case, it is not always true. However, we prove that such an action always exists when the foliation does not contain lightlike leaves, i.e. a pseudo-Riemannian Wadsley's Theorem. As an application, we show that every Lorentzian surface all of whose spacelike/timelike geodesics are closed, is finitely covered by $S^1\times \R$. It follows that every Lorentzian surface contains a non-closed geodesic.Comment: 14 page

Cellulose coating and chelation of antibacterial compounds for the protection of flax yarns against natural soil degradation.

Natural cellulosic fibres such as flax fibres present interesting mechanical properties as well as biodegradability, and by-products, such as short flax fibres, could be used to produce geotextiles to stabilise soils. Today, geotextiles are often made of coir fibres, which have a high lignin percentage leading to their slow degradation in soil. Fibres with a high cellulosic content, such as those of flax, exhibit lower resistance to soil degradation. This study investigates solutions to improve this parameter with a view to increasing their service life and therefore their credibility compared to coir fibres for geotextile applications. For this purpose, a cellulose coating of yarns made of short flax fibres was performed and its stability under a water flow was assessed. The ability to form a cellulose sheath was estimated by chromaticity measurements of flax fibres after applying a dye specific to lignin. Infrared spectrometry analysis to monitor the level of protection against degradation by cellulolytic enzymes was also carried out. It appears that the cellulose coating provides an efficient physical protection, preventing access of these enzymes to their fibrous substrate. Then, the possibility of conferring antibacterial properties on the cellulose coating by chelating phytoalexin molecules such as gramine on it was assayed and proven to be effective against soil cellulolytic bacteria such as Cellvibrio fulvus and Cellvibrio vulgaris. This study therefore establishes that coating flax yarns with cellulose associated with antibacterial molecules could contribute to obtaining a longer service life in soil for geotextiles manufactured from flax fibres

Advancing Implementation of Nuclear Decommissioning and Environmental Remediation Programmes

Significant progress has been achieved in recent years in terms of addressing the legacies from the early development of nuclear energy, including the decommissioning of redundant research and fuel cycle facilities, research reactors and power plants, and the remediation of sites affected by past uranium mining and processing operations. Some countries are moving forward with dealing with these legacies, and accordingly have built up appropriate technical resources and expertise, but many national programmes still face very significant challenges. However some factors constraining progress in addressing legacies from the past remain.There is for that reason a need to better understand the global situation and to analyse the barriers impeding the implementation of decommissioning and environmental remediation programmes, with the aim of outlining actions that may improve current situations where progress is impaired. The IAEA 'CIDER' project was launched in March 2013 in support of these objectives and with the support of other international organisations, particularly the European Commission and the European Bank for Reconstruction and Development. The present document aims to support the development of adequate policies in IAEA Member States for decommissioning and environmental remediation, addressing in essence the following three fundamental questions: - What are the motivations for implementing decommissioning and environmental remediation? - What are the main constraints hindering progress of decommissioning and environmental remediation programmes? - What are the solutions for overcoming these constraints, taking account of experience from programmes under implementation? This document, prepared in close collaboration with the IAEA, makes concise yet comprehensive proposals in answer to those questions, drawn from the results of a global survey performed in advance of the CIDER project and on the more extensive analysis provided in the CIDER project report, which was elaborated by expert groups from IAEA Member States.JRC.A.4-Nuclear Safety and Securit

Strong interactions in air showers

We study the role new gauge interactions in extensions of the standard model play in air showers initiated by ultrahigh-energy cosmic rays. Hadron-hadron events remain dominated by quantum chromodynamics, while projectiles and/or targets from beyond the standard model permit us to see qualitative differences arising due to the new interactions.Comment: 35 pages, 12 figures. Accepted for publication in JCA

Cross-cultural validation and analysis of responsiveness of the QUALIOST(®): QUAlity of Life questionnaire In OSTeoporosis

BACKGROUND: The QUALIOST(® )was designed for use with the SF-36 to measure established osteoporosis-specific quality of life (QoL). The reliability (internal consistency and test-retest) and validity of the questionnaire were established in a stand-alone psychometric validation study. The objective of this paper is to provide additional information on the instrument's responsiveness using clinical trial data, along with the reliability and validity of translated versions. METHODS: The Spinal Osteoporosis Therapeutic Intervention (SOTI) was an international clinical trial comparing strontium ranelate to placebo on the occurrence of new vertebral fracture in patients with postmenopausal osteoporosis. QoL was a secondary endpoint, assessed using the SF-36 and QUALIOST(® )at baseline and every six months, with the main analysis at 3-year follow-up. Questionnaire acceptability, analysis of the hypothesised structure, internal consistency reliability and responsiveness to clinical change over time were assessed at the 3-year follow up. RESULTS: 1592 patients from 11 countries completed at least one QoL questionnaire. The psychometric properties of the questionnaires were assessed on cross-sectional (N = 1486) and longitudinal (N = 1288) data. Item discriminant validity of the QUALIOST(® )was excellent, as was item convergent validity, with 100% of item-scale correlations being above the 0.40 level. Internal consistency reliability was also extremely good, with high Cronbach's alpha scores above the 0.70 benchmark. Responsiveness results were consistent for all QUALIOST(® )scores, indicating that greater decreases in QoL corresponded to greater numbers of fractures experienced. QUALIOST(® )scores also differed according to the type of fracture suffered. This was demonstrated by increased effect sizes for more severe vertebral fractures (clinical vertebral and painful vertebral). In comparing responsiveness, the QUALIOST(® )scores were generally more consistent than those of the SF-36. Most notably, the QUALIOST(® )was more responsive with regard to painful vertebral fractures than the SF-36. CONCLUSION: The QUALIOST(® )is a reliable and valid tool for measuring QoL in postmenopausal osteoporotic women. Being available in several validated language versions, it is ready to be used in a variety of settings, including international clinical trials