Flow-History-Dependent Behavior in Entangled Polymer Melt Flow with Multiscale Simulation

Polymer melts represent the flow-history-dependent behavior. To clearly show this behavior, we have investigated flow behavior of an entangled polymer melt around two cylinders placed in tandem along the flow direction in a two dimensional periodic system. In this system, the polymer states around a cylinder in downstream side are different from the ones around another cylinder in upstream side because the former ones have a memory of a strain experienced when passing around the cylinder in upstream side but the latter ones do not have the memory. Therefore, the shear stress distributions around two cylinders are found to be different from each other. Moreover, we have found that the averaged flow velocity decreases accordingly with increasing the distance between two cylinders while the applied external force is constant. While this behavior is consistent with that of the Newtonian fluid, the flow-history-dependent behavior enhances the reduction of the flow resistance.Comment: 6 pages, 3 figures, Proceedings of 5th International Mini-Symposium on Liquid

Seismic interpretation and generation of key depth structure surfaces within the Devonian and Carboniferous of the Central North Sea, Quadrants 25 – 44 area

This report details the rationale, methodology and results of a regional seismic interpretation of the western margin of the Central North Sea (CNS) area, specifically over the Mid North Sea High area, the offshore extension of the Northumberland Trough and the Forth Approaches area. The aim of the interpretation was to create maps that show the distribution of Palaeozoic basins and highs, and where possible interpret key Devono-Carboniferous surfaces and main structural elements in order to build a tectono-stratigraphic model of the Palaeozoic geology. Some 50,000 line kilometres of predominantly 2D seismic data have been interpreted and tied to key released wells in the study area. The seismic and well data were augmented by donated reports from sponsor companies. A set of 5 depth structure maps of selected Palaeozoic horizons has been produced for the pre-Permian succession. These maps provide a key element to aid assessment of the petroleum prospectivity of the Palaeozoic within the study area. The surfaces, with a grid spacing of 5000 m, give a regional view of the topography of the horizons, and comprise: Upper Permian Base Zechstein Group; Lower Carboniferous near Top Scremerston Formation; Lower Carboniferous near Top Fell Sandstone Formation; Lower Carboniferous near Top Cementstone Formation; and Middle Devonian near Top Kyle Limestone Group. The regional structure map of the area constructed for this report and observations made from the seismic data, have been integrated with peer reviewed published information to describe a tectonostratigraphic model for the region (Leslie et. al., 2015). A new pre-Permian subcrop map is presented here that builds on existing publications (Smith,1985a, b; Kombrink et al., 2010) and incorporates all relevant new well penetrations since the previous map was published. The well dataset has been either validated or re-interpreted before being integrated with the new seismic interpretation (Kearsey et al., 2015). Figure 10 in Section 3.3.1 below summarises the regional structures referred to in the general observations listed below. General observations on the structures defined across Quadrants 29, 30, 31, 37, 38 and 39: The Middle-Upper Devonian basins and highs follow a NW-SE trend across Quadrants 29-30 and 37-38; Lower Carboniferous sequences (Tournaisian and Visean) are interpreted to be present in depocentres across much of the area covered by Quadrants 29 to 38; wells, mainly drilled on the structural highs, constrain the edge of the Lower Carboniferous basins; There is a structurally complicated area in the southernmost part of Quadrant 38 which comprises a folded Visean and probably Namurian succession. The structure can be interpreted either as an anticlinal rollover on a low-angle fault, or as a compressional anticlinal fold (see Figure 17 below). The structure trends broadly NNE-SSW, plunging northwards into Quadrant 38

Collaborative coaching and learning in midwifery clinical placements: an evaluation

The model of coaching and collaborative learning is based on the nursing model of collaborative learning in practice developed at University of East Anglia and support by Health Education, East of England. The model was adapted to fit the midwifery antenatal and postnatal ward where it was trialled between September 2016 and August 2017. During the implementation students, coaches, mentors and other staff on the ward areas were supported by the practice development midwife. Evaluation data was collected in the normal module evaluations and showed overall satisfaction with the model and the opportunities for sharing learning. The model is now being rolled out to other placement areas. Keys to success include good preparation of the clinical placement areas and supported from a practice educator

A Candidate Protoplanet in the Taurus Star Forming Region

HST/NICMOS images of the class I protostar TMR-1 (IRAS04361+2547) reveal a faint companion with 10.0" = 1400 AU projected separation. The central protostar is itself resolved as a close binary with 0.31" = 42 AU separation, surrounded by circumstellar reflection nebulosity. A long narrow filament seems to connect the protobinary to the faint companion TMR-1C, suggesting a physical association. If the sources are physically related then we hypothesize that TMR-1C has been ejected by the protobinary. If TMR-1C has the same age and distance as the protobinary then current models indicate its flux is consistent with a young giant planet of several Jovian masses.Comment: 16 pages, 1 figure, Accepted by Astrophysical Journal Letters, Related information is available at http://www.extrasolar.co

An experimental demonstration that early-life competitive disadvantage accelerates telomere loss

Adverse experiences in early life can exert powerful delayed effects on adult survival and health. Telomere attrition is a potentially important mechanism in such effects. One source of early-life adversity is the stress caused by competitive disadvantage. Although previous avian experiments suggest that competitive disadvantage may accelerate telomere attrition, they do not clearly isolate the effects of competitive disadvantage from other sources of variation. Here, we present data from an experiment in European starlings ( Sturnus vulgaris ) that used cross-fostering to expose siblings to divergent early experience. Birds were assigned either to competitive advantage (being larger than their brood competitors) or competitive disadvantage (being smaller than their brood competitors) between days 3 and 12 post-hatching. Disadvantage did not affect weight gain, but it increased telomere attrition, leading to shorter telomere length in disadvantaged birds by day 12. There were no effects of disadvantage on oxidative damage as measured by plasma lipid peroxidation. We thus found strong evidence that early-life competitive disadvantage can accelerate telomere loss. This could lead to faster age-related deterioration and poorer health in later life. </jats:p

Transport coefficients of multi-particle collision algorithms with velocity-dependent collision rules

Detailed calculations of the transport coefficients of a recently introduced particle-based model for fluid dynamics with a non-ideal equation of state are presented. Excluded volume interactions are modeled by means of biased stochastic multiparticle collisions which depend on the local velocities and densities. Momentum and energy are exactly conserved locally. A general scheme to derive transport coefficients for such biased, velocity dependent collision rules is developed. Analytic expressions for the self-diffusion coefficient and the shear viscosity are obtained, and very good agreement is found with numerical results at small and large mean free paths. The viscosity turns out to be proportional to the square root of temperature, as in a real gas. In addition, the theoretical framework is applied to a two-component version of the model, and expressions for the viscosity and the difference in diffusion of the two species are given.Comment: 31 pages, 8 figures, accepted by J. Phys. Cond. Matte

Tectonic synthesis and contextual setting for the Central North Sea and adjacent onshore areas, 21CXRM Palaeozoic Project

This report is designed simply to provide a summary tectonic outline and contextual setting against which offshore seismic and well data relating to the Devono-Carboniferous evolution of the Central North Sea, Forth Approaches, and adjacent UK onshore region can be considered. This summary is intended to help better frame the questions that will arise during interrogation of that data; the findings that result from that analysis are presented elsewhere in the report series (Arsenikos et al., 2015; Kimbell & Williamson, 2015; Monaghan et al., 2015). Apparently contradictory, wrench- or extension-dominated patterns of Lower Carboniferous basin development are recorded in the Forth Approaches, Quadrant 29, North Dogger and Silverpit basins of the Central North Sea, as well as the Midland Valley of Scotland (MVS) and Northumberland and Solway basins onshore. Partitioning Carboniferous deformation across inherited pre-existing Caledonian or Tornquist structures is likely to be an important control on the tectonic architecture developed in these regions during intervals of the geological record in the Carboniferous. Onshore, spatially separate but contemporaneous domains of extension-dominated tectonics versus wrench-dominated tectonics explain the contrasting tectonic framework of the MVS/Forth Approaches region (wrench-dominated) compared with Northumberland Basin (classic ‘stags head’ structure). NE-SW trending Caledonian inheritance strongly controls the domain boundaries and the patterns of deformation created in each of these domains. Offshore, in the Devono-Carboniferous basins of the Central North Sea, the likelihood that strain is partitioned in a similar way across features inherited from the NW-SE Tornquist trend is proposed and examined. The data currently under consideration suggests that a NW-SE trending wrench-dominated domain is spatially associated with the region underlain by the Dogger Granite pluton; domains affected by extension-dominated tectonics appear to be arranged on either side of that feature, namely the Quadrant 29 and North Dogger basins to the NE, and the Silverpit Basin to the SW. Extension is expressed as a NE-SW directed stretch in both of these domains. Patterns of broadly N-S trending fold axes need to be carefully assessed in terms of their structural setting, as folding cannot implicitly be linked with inversion/compression when partitioned strains are developed. Superficially similar features can develop in the MVS in dextral transpression, in north Northumberland buttressed around the Cheviot Granite in overall dextral wrench, and as superimposed late compressional folds in end-Variscan convergence, for example in the Boldon syncline of County Durham. Offshore, similar inversion effects can be seen in the patterns of transpressive faulting associated with features such as the Murdoch Ridge, and with examples of superimposed NE-SW trending extensional faults active in the latest Carboniferous to early Permian

Feynman graph polynomials

The integrand of any multi-loop integral is characterised after Feynman parametrisation by two polynomials. In this review we summarise the properties of these polynomials. Topics covered in this article include among others: Spanning trees and spanning forests, the all-minors matrix-tree theorem, recursion relations due to contraction and deletion of edges, Dodgson's identity and matroids.Comment: 35 pages, references adde

Multiscale Simulation of History Dependent Flow in Polymer Melt

We have developed a new multiscale simulation technique to investigate history-dependent flow behavior of entangled polymer melt, using a smoothed particle hydrodynamics simulation with microscopic simulators that account for the dynamics of entangled polymers acting on each fluid element. The multiscale simulation technique is applied to entangled polymer melt flow around a circular obstacle in a two-dimensional periodic system. It is found that the strain-rate history-dependent stress of the entangled polymer melt affects its flow behavior, and the memory in the stress causes nonlinear behavior even in the regions where ${\rm Wi} \le 1$. The spatial distribution of the entanglements $$ is also investigated. The slightly low entanglement region is observed around the obstacle and is found to be broaden in the downstream region.Comment: 4 pages, 3 figure