682 research outputs found
Aerodynamic characteristics of a large-scale V/STOL transport model with tandem lift fans mounted at mid-semispan of the wing
Aerodynamic characteristics of V/STOL transport model with tandem lift fans mounted at mid-semispan of win
Does landscape-scale conservation management enhance the provision of ecosystem services?
Biodiversity conservation approaches are increasingly being implemented at the landscape-scale to support the maintenance
of metapopulations and metacommunities. However, the impact of such interventions on the provision of ecosystem services
is less well defined. Here we examine the potential impacts of landscape-scale conservation initiatives on ecosystem
services, through analysis of five case study areas in England and Wales. The provision of multiple ecosystem services was
projected according to current management plans and compared with a baseline scenario. Multicriteria analysis indicated
that in most cases landscape-scale approaches lead to an overall increase in service provision. Consistent increases were
projected in carbon storage, recreation and aesthetic value, as well as biodiversity value. However, most study areas
provided evidence of trade-offs, particularly between provisioning services and other types of service. Results differed
markedly between study areas, highlighting the importance of local context. These results suggest that landscape-scale
conservation approaches are likely to be effective in increasing ecosystem service provision, but also indicate that associated
costs can be significant, particularly in lowland areas
The SKA Particle Array Prototype: The First Particle Detector at the Murchison Radio-astronomy Observatory
We report on the design, deployment, and first results from a scintillation
detector deployed at the Murchison Radio-astronomy Observatory (MRO). The
detector is a prototype for a larger array -- the Square Kilometre Array
Particle Array (SKAPA) -- planned to allow the radio-detection of cosmic rays
with the Murchison Widefield Array and the low-frequency component of the
Square Kilometre Array. The prototype design has been driven by stringent
limits on radio emissions at the MRO, and to ensure survivability in a desert
environment. Using data taken from Nov.\ 2018 to Feb.\ 2019, we characterize
the detector response while accounting for the effects of temperature
fluctuations, and calibrate the sensitivity of the prototype detector to
through-going muons. This verifies the feasibility of cosmic ray detection at
the MRO. We then estimate the required parameters of a planned array of eight
such detectors to be used to trigger radio observations by the Murchison
Widefield Array.Comment: 17 pages, 14 figures, 3 table
Emplotment as Epic in Archaeological Writing: The Site Monograph as Narrative
To emplot a narrative as epic is to present a story of vast scope and multiple plots as a legitimate member of a tradition of other such stories. This article argues that emplotment as epic is the broadest of three levels of plot in archaeological writings. At that level, the site monograph emerges as a characteristically archaeological form of narrative, fundamental to archaeology as a discipline and a source of chronic anxiety for archaeologists. The ‘stories’ told in site monographs are epic in length, diversity of materials covered and multiplicity of themes, plots and authors. Indeed, the more complexities of that sort the better, since those are features that help to emplot the work as good archaeology
Electroactive biomimetic collagen-silver nanowire composite scaffolds
Electroactive biomaterials are widely explored as bioelectrodes and as scaffolds for neural and cardiac regeneration. Most electrodes and conductive scaffolds for tissue regeneration are based on synthetic materials that have limited biocompatibility and often display large discrepancies in mechanical properties with the surrounding tissue causing problems during tissue integration and regeneration. This work shows the development of a biomimetic nanocomposite material prepared from self-assembled collagen fibrils and silver nanowires (AgNW). Despite consisting of mostly type I collagen fibrils, the homogeneously embedded AgNWs provide these materials with a charge storage capacity of about 2.3 mC cm-2 and a charge injection capacity of 0.3 mC cm-2, which is on par with bioelectrodes used in the clinic. The mechanical properties of the materials are similar to soft tissues with a dynamic elastic modulus within the lower kPa range. The nanocomposites also support proliferation of embryonic cardiomyocytes while inhibiting the growth of both Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis. The developed collagen/AgNW composites thus represent a highly attractive bioelectrode and scaffold material for a wide range of biomedical applications
Combined X-Ray and Fully Leaky Guided Mode Studies of the Smectic Layer and Optic Tensor Configuration in a Ferroelectric Liquid-Crystal Cell
B. Hodder, J. Roy Sambles, S. Jenkins, and R. M. Richardson, Physical Review Letters, Vol. 85, pp. 3181 - 3184 (2000). "Copyright © 2000 by the American Physical Society."X-ray scattering together with optical characterization using fully leaky guided modes have been used for the first time to study the same ferroelectric liquid-crystal cell. This enables direct calculation of an accurate cone and chevron description of the liquid-crystal director profile since the layer structure and optic tensor configuration are both well known
Tilt order parameters, polarity and inversion phenomena in smectic liquid crystals
The order parameters for the phenomenological description of the smectic-{\it
A} to smectic-{\it C} phase transition are formulated on the basis of molecular
symmetry and structure. It is shown that, unless the long molecular axis is an
axis of two-fold or higher rotational symmetry, the ordering of the molecules
in the smectic-{\it C} phase gives rise to more than one tilt order parameter
and to one or more polar order parameters. The latter describe the indigenous
polarity of the smectic-{\it C} phase, which is not related to molecular
chirality but underlies the appearance of spontaneous polarisation in chiral
smectics. A phenomenological theory of the phase transition is formulated by
means of a Landau expansion in two tilt order parameters (primary and
secondary) and an indigenous polarity order parameter. The coupling among these
order parameters determines the possibility of sign inversions in the
temperature dependence of the spontaneous polarisation and of the helical pitch
observed experimentally for some chiral smectic-{\it } materials. The
molecular interpretation of the inversion phenomena is examined in the light of
the new formulation.Comment: 12 pages, 5 figures, RevTe
Personal, Political, Pedagogic: Challenging the binary bind in archaeological teaching, learning and fieldwork
yesIn this paper we consider how we can undercut the various binaries of gender and sexuality in
archaeological practice, and particularly in our teaching. We argue that taking an assemblage theory approach enables us to look at the multiplicity of identities of those practicing archaeology as different and intersecting assemblages that bring one another into being through their connections at different scales. In particular, we examine how this approach can be applied to archaeological pedagogy and how this in turn enables us to move away from modern binary distinctions about sex and gender identities from the "bottom up", fostering an approach in our students that will then go on to be developed in professional practice
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