7,187 research outputs found
Pathways to phase-out contentious inputs
Workshop "Pathways to phase-out contentious inputs" with the following three inputs:
• Replacement of Contentious Inputs in Organic Farming Systems (RELACS) – a comprehensive Horizon 2020 project, Veronika Maurer, Research Institute of Organic Agriculture (FiBL), CH
• Pathways to phase-out contentious inputs from organic agriculture in Europe – Research overview and preliminary results, Ulrich Schmutz, Coventry University, UK
• Lessons learned from phase-outs – the case of the peat phase-out in the United Kingdom, Judith Conro
Pathways to phase-out contentious inputs
Workshop "Pathways to phase-out contentious inputs" with the following three inputs:
• Replacement of Contentious Inputs in Organic Farming Systems (RELACS) – a comprehensive Horizon 2020 project, Veronika Maurer, Research Institute of Organic Agriculture (FiBL), CH
• Pathways to phase-out contentious inputs from organic agriculture in Europe – Research overview and preliminary results, Ulrich Schmutz, Coventry University, UK
• Lessons learned from phase-outs – the case of the peat phase-out in the United Kingdom, Judith Conro
Part-products of -restricted integer compositions
If is a cofinite set of positive integers, an "-restricted composition
of " is a sequence of elements of , denoted
, whose sum is . For uniform random
-restricted compositions, the random variable is asymptotically lognormal. The proof is
based upon a combinatorial technique for decomposing a composition into a
sequence of smaller compositions.Comment: 18 page
Measuring your Garden Footprint
The work reports on a Garden Organic (working name of Henry Doubleday Research Association, Coventry UK) members experiment in 2007. Garden Organic members were surveyed with a detailed paper questionnaire to calculate an average gardening footprint of committed (self-selected) organic gardeners in the UK. This was used to develop a garden footprinting methodology and to create a benchmark of committed organic gardening in the UK. This was then compared to commerical orangic growing and to other household activities with their respective footprint and potential for improvement.
Summary findings:
(116 responses 85% reponse rate).
o The average UK food and drink ecological footprint is around 1.4 gha/ha
o About a quarter of this (25% =0.35 gha/ha) is due to fruit and vegetable production and consumption
o Our members taking part in this survey produced about half their own with an average ecological footprint for their gardening activities of 0.15gha/ha
o This equates to a ‘saving’ of around 0.02 gha/ha, or a saving of 13% on the average UK footprint attributable to fruit and vegetables
o This equates to about a 6% savings in total food and drink footprint which is on a par with double glazing, replacing an old boiler or reduced car use
o Our members could take measures to reduce their gardening footprint by:
- buying ‘good quality’ tools that last a long time
- using manual tools where possible
- buying ‘good quality’ power tools and keeping them well maintained to reduce relative fuel consumption and embedded energy costs
- by being wary of substituting long ‘food chains’ for long ‘supply chains’ of products that they use in their gardens
- by trying to close nutrient cycles; e.g. producing amendments at home (e.g. comfrey), fixing N in situ (e.g. green manures), composting biodegradable materials
- using protected cropping only where necessary and in an ‘environmentally friendly way’ e.g. reuse of materials, second hand strucutures etc.
- reducing fridge and/or freezer use; e.g. turning them off when not in use and buying new A++-rated energy-efficient appliances
o It is still uncertain what positive contributions waste and recycling can make in reducing gardening footprint as some of the issues are quite complex. Many are the subject of ongoing research.
o Producing food at home leads to other ecologically efficient habits as witnessed by the low overall ecological and carbon footprints of our members.
o It is important to realise that as you reduce your personal footprint the proportion due to services and infrastructure spent on your behalf becomes much more important. Solutions to this are likely to be collective and political. Many are likely to revolve around community based activities
Long uninterrupted photometric observations of the Wolf-Rayet star EZ CMa by the Toronto {\em{BRITE}} satellite reveal a very fast apsidal motion
Context. The variability of the Wolf-Rayet star EZ CMa has been documented
for close to half a century, and a clear periodicity of 3.7 days is
established. However, all attempts to prove that it is a binary have failed
because the photometric, spectroscopic, and polarimetric variations are not
coherent over more than a few orbital cycles.
Aims. In this letter we show that the lack of coherence in the variability
can be explained with a very rapid apsidal motion in a binary orbit.}
Methods. We measured the times of minima in a recently published
exceptionally long photometric light curve obtained by the Toronto
{\emph{BRITE}} satellite. The apsidal motion and the system eccentricity are
determined from the length of the time intervals between these minima, which
alternate in their duration, following a pattern that is clearly associated
with apsidal motion. These minima are superposed on brightness enhancements of
the emission from a shock zone, which occur at about the times of periastron
phases.
Results. We determine the orbital periodicity, d, and the
period of the apsidal motion, d, which together yield an
average sidereal period of d. The eccentricity is found to be
close to 0.1. The rate of periapsis retreat changes significantly over the
period of observation and is determined to be at
the beginning of the observing period and at the
end.
Conclusions. We demonstrate that by introducing a fast apsidal motion, the
basic photometric variability is very well explained. The binary nature of EZ
CMa is now established. This might imply that other apparently single
Wolf-Rayet stars that emit hard X-rays, similar to EZ CMa, are also binaries.Comment: A&A Letter in press, 5 pages, 3 figure
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