439 research outputs found

    Forbedrede udearealer i økologisk ægproduktion

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    Med henblik på at styrke forsknings- og udviklingsindsatsen inden for økologisk fjerkræproduktion, blev det muligt med finansiering fra Direktoratet for FødevareErhverv, i 2001 at påbegynde udviklingsprojektet ”Fjerkræets udearealer ved økologisk produktion”. Projektet tog udgangspunkt i en række interessetilkendegivelser fra fjerkræproducenter og andre interesserede indenfor økologisk fjerkræproduktion, og projektet blev planlagt i et samarbejde mellem • Brancheforeningen for Økologiske Æg- og Fjerkræproducenter • Dansk Erhvervsfjerkræ • Landsforeningen for Økologisk Jordbrug • Landskontoret for Fjerkrærådgivning og • Danmarks JordbrugsForskning som koordinerende partner Det var en grundlæggende ide i projektet at tage udgangspunkt i de medvirkende producenters allerede opbyggede erfaringsgrundlag og idéer til videre udvikling. En del af projektet tog udgangspunkt i en interessetilkendegivelse fra en gruppe ægproducenter, ”Hønsegården” A.m.b.a., der havde et samarbejde om videndeling og afsætning. Producenterne havde i samarbejde med Landskontoret for Fjerkrærådgivning identificeret udearealerne (hønsegårdene) som et centralt område, hvor der var behov for yderligere viden om den mest hensigtsmæssige indretning og drift i forhold til såvel hønernes produktivitet og velfærd som miljøeffekter. Rapporten beskriver de opnåede resultater fra denne del af projektet og på grundlag heraf gives anbefalinger til, hvorledes udearealerne mest hensigtsmæssigt bør indrettes

    BioConcens: Biomass and bioenergy production agriculture – consequences for soil fertility, environment, spread of animal parasites and socio-economy

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    The research programme called “international research cooperation and organic integrity” was commenced for a period 2006-2010. It is coordinated by DARCOF (The Danish Research Centre for Organic Farming). The whole programme, with acronym DARCOF III, consists of 15 projects (http://www.darcof.dk/research/darcofiii/index.html). One of them is BIOCONCENS - Biomass and bioenergy production in organic farming – consequences for soil fertility, environment, spread of animal parasites and socio-economy (http://www.bioconcens.elr.dk/uk/). The production of bioenergy in organic agriculture (OA) can reduce its dependency of fossil fuels and decrease green house gasses emission; consequently it will increase sustainability of organic farms. Biorefinery concept based on co-production of biogas, bioethanol and protein fodder in organic farming will be developed within the BIOCONCENS project and the background for the project and the different work packages will be presented in this paper

    Biomass and bioenergy production in organic agriculture. Consequences for soil fertility, environment, spread of animal parasites and socio-economy. BioConcnes, a 4-year interdisciplinary project.

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    Energy production and energy use in organic agriculture (OA) need to be addressed in order to reduce the reliance on non-renewable fossil fuels and minimize greenhouse gas (GHG) emissions. Thus, there is an obligation to find consensus between the apparent opposing aims of renewable (bio) energy production and soil fertility in OA. This project aims at designing and evaluate a combined concept for biomass and bio-energy production in OA, while considering soil fertility

    Magnetic fields in protoplanetary disks

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    Magnetic fields likely play a key role in the dynamics and evolution of protoplanetary discs. They have the potential to efficiently transport angular momentum by MHD turbulence or via the magnetocentrifugal acceleration of outflows from the disk surface, and magnetically-driven mixing has implications for disk chemistry and evolution of the grain population. However, the weak ionisation of protoplanetary discs means that magnetic fields may not be able to effectively couple to the matter. I present calculations of the ionisation equilibrium and magnetic diffusivity as a function of height from the disk midplane at radii of 1 and 5 AU. Dust grains tend to suppress magnetic coupling by soaking up electrons and ions from the gas phase and reducing the conductivity of the gas by many orders of magnitude. However, once grains have grown to a few microns in size their effect starts to wane and magnetic fields can begin to couple to the gas even at the disk midplane. Because ions are generally decoupled from the magnetic field by neutral collisions while electrons are not, the Hall effect tends to dominate the diffusion of the magnetic field when it is able to partially couple to the gas. For a standard population of 0.1 micron grains the active surface layers have a combined column of about 2 g/cm^2 at 1 AU; by the time grains have aggregated to 3 microns the active surface density is 80 g/cm^2. In the absence of grains, x-rays maintain magnetic coupling to 10% of the disk material at 1 AU (150 g/cm^2). At 5 AU the entire disk thickness becomes active once grains have aggregated to 1 micron in size.Comment: 11 pages, 11 figs, aastex.cls. Accepted for publication in Astrophysics & Space Science. v3 corrects bibliograph

    Production of biomass and bioenergy in organic agriculture and its consequences for soil quality, environment, biodiversity and socio-economy

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    Production of bioenergy in organic agriculture may be implemented in the future to reduce the reliance on non-renewable fossil fuels and minimize greenhouse gas (GHG) emissions. Therefore it is important to assess the potential effect this may have on soil quality and biological parameters. This project aims at designing and evaluate a combined concept for biomass and bio-energy production in OA, while considering soil bio-geo-chemical cycling of plant nutrients and biodiversity of the soil microbiota

    Against all odds? Forming the planet of the HD196885 binary

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    HD196885Ab is the most "extreme" planet-in-a-binary discovered to date, whose orbit places it at the limit for orbital stability. The presence of a planet in such a highly perturbed region poses a clear challenge to planet-formation scenarios. We investigate this issue by focusing on the planet-formation stage that is arguably the most sensitive to binary perturbations: the mutual accretion of kilometre-sized planetesimals. To this effect we numerically estimate the impact velocities dvdv amongst a population of circumprimary planetesimals. We find that most of the circumprimary disc is strongly hostile to planetesimal accretion, especially the region around 2.6AU (the planet's location) where binary perturbations induce planetesimal-shattering dvdv of more than 1km/s. Possible solutions to the paradox of having a planet in such accretion-hostile regions are 1) that initial planetesimals were very big, at least 250km, 2) that the binary had an initial orbit at least twice the present one, and was later compacted due to early stellar encounters, 3) that planetesimals did not grow by mutual impacts but by sweeping of dust (the "snowball" growth mode identified by Xie et al., 2010b), or 4) that HD196885Ab was formed not by core-accretion but by the concurent disc instability mechanism. All of these 4 scenarios remain however highly conjectural.Comment: accepted for publication by Celestial Mechanics and Dynamical Astronomy (Special issue on EXOPLANETS

    Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

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    A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
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