376 research outputs found
Generation of Multiple Circular Walls on a Thin Film of Nematic Liquid Crystal by Laser Scanning
We found that multiple circular walls (MCW) can be generated on a thin film
of a nematic liquid crystal through a spiral scanning of a focused IR laser.
The ratios between radii of adjacent rings of MCW were almost constant. These
constant ratios can be explained theoretically by minimization of the Frank
elastic free energy of nematic medium. The director field on a MCW exhibits
chiral symmetry-breaking although the elastic free energies of both chiral MCWs
are degenerated, i.e., the director on a MCW can rotate clockwise or
counterclockwise along the radial direction.Comment: 10 pages, 5 figures. Submitted to Chemical Physics Letters 2nd
Editio
Linking benthic biodiversity to the functioning of coastal ecosystems subjected to river runoff (NW Mediterranean)
Continental particulate organic matter (POM) plays a major role in the functioning of coastal marine ecosystems as a disturbance as well as an input of nutrients. Relationships linking continental inputs from the Rhone River to biodiversity of the coastal benthic ecosystem and fishery production were investigated in the Golfe du Lion (NW Mediterranean Sea). Macrobenthic community diversity decreased when continen¬tal inputs of organic matter increased, whereas ecosystem production, measured by common sole (Solea solea) fishery yields in the area, increased. Decreases in macrobenthic diversity were mainly related to an increasing abundance of species with specific functional traits, particularly deposit-feeding polychaetes. The decrease in macrobenthic diversity did not result in a decrease, but an increase in ecosystem production, as it enhanced the transfer of continental POM into marine food webs. The present study showed that it is necessary to consider functional traits of species, direct and indirect links between species, and feedback loops to understand the effects of biodiversity on ecosystem functioning and productivity
Structural properties of crumpled cream layers
The cream layer is a complex heterogeneous material of biological origin
which forms spontaneously at the air-milk interface. Here, it is studied the
crumpling of a single cream layer packing under its own weight at room
temperature in three-dimensional space. The structure obtained in these
circumstances has low volume fraction and anomalous fractal dimensions. Direct
means and noninvasive NMR imaging technique are used to investigate the
internal and external structure of these systems.Comment: 9 pages, 4 figures, accepted in J. Phys. D: Appl. Phy
Non-isothermal model for the direct isotropic/smectic-A liquid crystalline transition
An extension to a high-order model for the direct isotropic/smectic-A liquid
crystalline phase transition was derived to take into account thermal effects
including anisotropic thermal diffusion and latent heat of phase-ordering.
Multi-scale multi-transport simulations of the non-isothermal model were
compared to isothermal simulation, showing that the presented model extension
corrects the standard Landau-de Gennes prediction from constant growth to
diffusion-limited growth, under shallow quench/undercooling conditions.
Non-isothermal simulations, where meta-stable nematic pre-ordering precedes
smectic-A growth, were also conducted and novel non-monotonic
phase-transformation kinetics observed.Comment: First revision: 20 pages, 7 figure
Numerical Confirmation of Late-time t^{1/2} Growth in Three-dimensional Phase Ordering
Results for the late-time regime of phase ordering in three dimensions are
reported, based on numerical integration of the time-dependent Ginzburg-Landau
equation with nonconserved order parameter at zero temperature. For very large
systems () at late times, the characteristic length grows
as a power law, , with the measured in agreement with the
theoretically expected result to within statistical errors. In this
time regime is found to be in excellent agreement with the analytical
result of Ohta, Jasnow, and Kawasaki [Phys. Rev. Lett. {\bf 49}, 1223 (1982)].
At early times, good agreement is found between the simulations and the
linearized theory with corrections due to the lattice anisotropy.Comment: Substantially revised and enlarged, submitted to PR
Analyzing Science Education in the United Kingdom: Taking a System-Wide Approach
Increasing evidence suggests that individuals develop their understanding of science concepts in and out of school, using varied community resources and networks. Thus in contrast to historic research approaches that focus exclusively on single organizations and/or educational events, the current paper presents exploratory research in which we utilized specific community ecology analytical tools and approaches to describe and analyze the U.K. science education community as a whole. Data suggest that overall the U.K. science education community is highly interconnected, and collaborative within individual sectors and moderately interconnected and collaborative between sectors; schools and to a lesser degree universities were outliers to this pattern. An important conclusion was that management to maximize the effectiveness of science education the U.K. science education community would involve support for continued diversification of the number of science education entities in the system and encouragement of reciprocally collaborative, synergistic relationships. We posit that systemic research enables a broader, more comprehensive view of a system's strengths and weaknesses, offering useful insights into the structure and functioning of science education activities; insights that could help researchers, practitioners, and policy makers improve the overall quality of science education delivery for all
Museum Audio Description: The Problem of Textual Fidelity
Museums present a myriad of source texts, which are often highly ambiguous. Yet Museum Audio Description (AD) is sited in an AD tradition which advocates objectivity. In screen AD, researchers have examined multiple aspects of the translation decisions facing the describer-translator, considering the ways in which AD is shaped by the demands of the source text, the impact of AD on the recipient’s experience and how these aspects may relate to objectivity. We examine the extent to which these decisions may apply to museum AD or differ in a museum setting. We argue that the notion of the ‘source text’ for museums should be expanded beyond the visual elements of museum’s collections, encompassing the wider museum visiting experience. Drawing upon research from Museum Studies and Psychology, we explore the empirical evidence that characterises the experiences of mainstream sighted visitors and discuss the implications for museum AD. If it is to offer true access to the museum experience, then museum AD must consider not only the assimilation of visual information, but also the social, cognitive and emotional elements of visits. From this perspective, the emphasis is shifted from visual to verbal translation to the creative possibilities of re-creation in museum AD
Prevalence of pelagic dependence among coral reef predators across an atoll seascape
1)Coral reef food webs are complex, vary spatially and remain poorly understood. Certain large predators, notably sharks, are subsidised by pelagic production on outer reef slopes, but how widespread this dependence is across all teleost fishery target species and within atolls is unclear.
2)North Malé Atoll (Maldives) includes oceanic barrier as well as lagoonal reefs. Nine fishery target predators constituting ca. 55% of the local fishery target species biomass at assumed trophic levels 3‐5 were selected for analysis. Data were derived from carbon (δ13C), nitrogen (δ15N) and sulfur (δ34S) stable isotopes from predator white dorsal muscle samples, and primary consumer species representing production source end‐members.
3)Three‐source Bayesian stable isotope mixing models showed that uptake of pelagic production extends throughout the atoll, with predatory fishes showing equal planktonic reliance between inner and outer edge reefs. Median plankton contribution was 65‐80% for all groupers and 68‐88% for an emperor, a jack and snappers.
4)Lagoonal and atoll edge predators are equally at risk from anthropogenic and climate‐induced changes which may impact the linkages they construct, highlighting the need for management plans that transcend the boundaries of this threatened ecosystem
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