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Reflectance spectra of Mesosiderites: Implications for asteroid 4 Vesta
Oxygen isotopic data argues that HEDs and mesosiderites may be from the same parent body. A spectral survey of mesosiderites was done to determine their spectral properties in the visible and near-infrared and compare to HEDs
Generic occurrence of rings in rotating systems
In rotating scattering systems, the generic saddle-center scenario leads to
stable islands in phase space. Non-interacting particles whose initial
conditions are defined in such islands will be trapped and form rotating rings.
This result is generic and also holds for systems quite different from
planetary rings.Comment: 10 pages, 5 ps figures; uses elsart.sty and epsfig.sty Accepted in
Phys. Lett.
Inventory of ammonia emissions from UK agriculture 2009
The National Ammonia Reduction Strategy Evaluation System (NARSES) model (spreadsheet version) was used to estimate ammonia (NH3) emissions from UK agriculture for the year 2009. Year-specific livestock numbers and fertiliser N use were added for 2009 and revised for previous years. The estimate for 2009 was 231.8 kt NH3, representing a 2.3 kt increase from the previously submitted estimate for 2008. Backward and forward projections using the 2009 model structure gave estimates of 317, 245 and 244 kt NH3 for the years 1990, 2010 and 2020, respectively. This inventory reports emission from livestock agriculture and from nitrogen fertilisers applied to agricultural land. There are a number of other minor sources reported as ‘agriculture’ in the total UK emission inventory, including horses not kept on agricultural holdings, emissions from composting and domestic fertiliser use
Colouring of Pacific barkcloth: identification of the brown, red and yellow colourants used in the decoration of historic Pacific barkcloths
Barkcloth textiles made in the Pacific islands and collected by western explorers in the eighteenth and nineteenth centuries form part of many museum collections worldwide. Here high-performance liquid chromatography (HPLC) and X-ray fluorescence (XRF) were used on cloths that were highly coloured or pigmented specifically focussing on identifying the red, yellow and brown colorants. The cloths studied came from collections held at the Hunterian, University of Glasgow, the Economic Botany Collection, Royal Botanic Gardens Kew and the Centre for Textile Conservation and Technical Art History, University of Glasgow. HPLC analysis was carried out following a sequential extraction procedure to minimise changes to the colorants during extraction. A portable XRF was used so no invasive sampling was required. A small number of plant derived colorants were found, Morinda citrifolia, noni (morindin or morindone), Rubia tinctorum (madder), tree tannins and Curcuma longa (turmeric) plus an inorganic colorant, iron oxide. For 40 samples a single colorant was found while in the remaining 12 samples combinations of up to three colorants were found. Madder was found in only 2 samples on the same cloth. The morindone coloured samples were all red whereas morindin samples were both red and yellow. Morindin was used predominantly in combination with other colouring agents. A combination of iron ochre and organic colorant was found in 4 samples. These findings show that despite the numerous potential colorant sources for red, brown and yellow shades listed in the many accounts of historic barkcloth making, only five types of plant colourant and one inorganic pigment were found. There are a number of potential reasons for these findings. Some colours may have faded and so no longer appear coloured. It is also possible that, as some of these cloths were prepared specifically as gifts for visitors or for ceremonial uses, the makers used materials that they knew would retain their integrity over time. Perhaps, like artisans worldwide, experience had taught them that some colorants, although initially bright and vivid, faded over time
Lower bounds for nodal sets of Dirichlet and Neumann eigenfunctions
Let \phi\ be a Dirichlet or Neumann eigenfunction of the Laplace-Beltrami
operator on a compact Riemannian manifold with boundary. We prove lower bounds
for the size of the nodal set {\phi=0}.Comment: 7 page
The Scottish Nephrops Survey Phase II: The Processes that Underlie Quality Loss in the Whole Animal Compared to the Tailed Product
Comparison of treatment outcomes for superficial digital flexor tendonitis in national hunt racehorses
Self-replication and evolution of DNA crystals
Is it possible to create a simple physical system that is capable of replicating itself? Can such a system evolve interesting behaviors, thus allowing it to adapt to a wide range of environments? This paper presents a design for such a replicator constructed exclusively from synthetic DNA. The basis for the replicator is crystal growth: information is stored in the spatial arrangement of monomers and copied from layer to layer by templating. Replication is achieved by fragmentation of crystals, which produces new crystals that carry the same information. Crystal replication avoids intrinsic problems associated with template-directed mechanisms for replication of one-dimensional polymers. A key innovation of our work is that by using programmable DNA tiles as the crystal monomers, we can design crystal growth processes that apply interesting selective pressures to the evolving sequences. While evolution requires that copying occur with high accuracy, we show how to adapt error-correction techniques from algorithmic self-assembly to lower the replication error rate as much as is required
Designed to fail : a biopolitics of British Citizenship.
Tracing a route through the recent 'ugly history' of British citizenship, this article advances two central claims. Firstly, British citizenship has been designed to fail specific groups and populations. Failure, it argues, is a design principle of British citizenship, in the most active and violent sense of the verb to design: to mark out, to indicate, to designate. Secondly, British citizenship is a biopolitics - a field of techniques and practices (legal, social, moral) through which populations are controlled and fashioned. This article begins with the 1981 Nationality Act and the violent conflicts between the police and black communities in Brixton that accompanied the passage of the Act through the British parliament. Employing Michel Foucault's concept of state racism, it argues that the 1981 Nationality Act marked a pivotal moment in the design of British citizenship and has operated as the template for a glut of subsequent nationality legislation that has shaped who can achieve citizenship. The central argument is that the existence of populations of failed citizens within Britain is not an accident of flawed design, but is foundational to British citizenship. For many 'national minorities' the lived realities of biopolitical citizenship stand in stark contradistinction to contemporary governmental accounts of citizenship that stress community cohesion, political participation, social responsibility, rights and pride in shared national belonging
Simulation studies for dielectric wakefield programme at CLARA facility
Short, high charge electron bunches can drive high magnitude electric fields
in dielectric lined structures. The interaction of the electron bunch with this
field has several applications including high gradient dielectric wakefield
acceleration (DWA) and passive beam manipulation. The simulations presented
provide a prelude to the commencement of an experimental DWA programme at the
CLARA accelerator at Daresbury Laboratory. The key goals of this program are:
tunable generation of THz radiation, understanding of the impact of transverse
wakes, and design of a dechirper for the CLARA FEL. Computations of
longitudinal and transverse phase space evolution were made with Impact-T and
VSim to support both of these goals.Comment: 10 Pages, 4 Figures, Proceedings of EAAC2017 Conferenc
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