748 research outputs found
Arbeitsnetz zur Weiterentwicklung der Anbaukonzepte im Ökologischen Obstbau
Im Rahmen des Projektes ist eine Schwachstellenanalyse der Anbaukonzepte des ökologischen Obstbaus gefolgt von einer Erarbeitung von kurz- und langfristig umsetzbaren fundierten und praxisnahen Strategieansätzen zur Optimierung dieser Konzepte in enger Vernetzung von Praxisbetrieben, Beratung, angewandter Forschung und Grundlagenforschung sowie fachspezifischer Experten erfolgt. Das bundesweite Diskussionsforum aus Praktikern, Berater und Forschern, das zur laufenden Weiterentwicklung der Anbaumethoden geschaffen wurde, ist inzwischen eingespielt, arbeitet effizient und richtungsweisend. Dadurch werden laufenden Arbeiten zu verschiedenen Fragen optimal begleitet. Neu auftretende Fragen können rasch aufgegriffen und bearbeitet werden. Diese Form der Weiterentwicklung entspricht der ursprünglichen Struktur, die den Ökologischen Landbau hervorgebracht hat.
Für die wichtigsten ungelösten Problembereiche (Apfelwickler, Schorf, Regenflecken, Feuerbrand) konnten sehr effizient aus der Praxis heraus Strategien für Lösungsansätze erarbeitet und in Form von Projekten umgesetzt werden. Stein- und Beerenobst waren vor Beginn des Arbeitsnetzes stark vernachlässigte Bereiche. Durch die Aktivitäten im Arbeitsnetz wurden hier erstmals Schwachstellen erkannt und Handlungsbedarf formuliert. Aus dieser Arbeit sind Projektanträge sowohl im Stein- als auch im Beerenobst hervorgegangen, die die ermittelten Schwachstellen bearbeiten und in Zusammenarbeit mit der Praxis umsetzen sollen. In beiden Kulturen haben sich außerdem Aktivitäten etabliert, die in Zusammenarbeit mit den Versuchsanstalten und Züchtern eine Prüfung neuer Sorten unter ökologischen Anbaubedingungen in den Betrieben ermöglichen sollen. Für Kernobst wurde im Jahr 2005 ein Sorteninformationsnetz gegründet. Strategieansätze wurden aber nicht nur für eine Optimierung der Wirtschaftlichkeit sondern auch der Nachhaltigkeit der Anbaukonzepte erarbeitet. So wurden erste Konzepte für eine ökologische Aufwertung von Obstanlagen angedacht, die derzeit in einigen Praxisbetrieben getestet werden.
Durch die Diskussion der Strategieansätze der einzelnen AKs im Rahmen der jährlichen Veranstaltung mit den Praktikern ergibt sich die Möglichkeit zur interdisziplinären Verknüpfung einzelner Projektergebnisse zu einem praxistauglichen Gesamtkonzept. Die Arbeit im Arbeitsnetz hat daher entscheidend dazu beigetragen, den ökologischen Obstbau sicherer, wirtschaftlicher und nachhaltiger zu gestalten
Maxwellian Neutron Spectrum generation and Stellar Cross-Section measurements: measurement of the 197Au(n,γ) MACS
Maxwellian-averaged cross-sections (MACS) are needed as an input for the models
of stellar s- and r-processes nucleosynthesis. MACS can be obtained from activation
measurements, irradiating a sample with the neutron field generated by the 7Li(p,n)7Be reaction
at 1912 keV proton energy. At this energy, the neutron energy spectrum is close (R2≤0.9) to a
Maxwellian one of kT=25 keV. However, it was shown that shaping the energy of the incident
proton beam is possible to generate a neutron field with an energy spectrum much closer to a
real Maxwellian (R2>0.995), therefore avoiding or minimizing corrections in the MACS
calculation. We show a preliminary result of an experiment performed at JRC-IRMM (Geel) to
confirm our method. We have measured the MACS30 (kT=30 keV) of the 197Au(n,γ) reaction,
at CNA (Seville). We obtained 612 mb, in good agreement with the latest measurements
The experimental realization of a two-dimensional colloidal model system
We present the technical details of an experimental method to realize a model
system for 2D phase transitions and the glass transition. The system consists
of several hundred thousand colloidal super-paramagnetic particles confined by
gravity at a flat water-air interface of a pending water droplet where they are
subjected to Brownian motion. The dipolar pair potential and therefore the
system temperature is not only known precisely but also directly and
instantaneously controllable via an external magnetic field B. In case of a one
component system of monodisperse particles the system can crystallize upon
application of B whereas in a two component system it undergoes a glass
transition. Up to 10000 particles are observed by video microscopy and image
processing provides their trajectories on all relative length and time scales.
The position of the interface is actively regulated thereby reducing surface
fluctuations to less than one micron and the setup inclination is controlled to
an accuracy of 1 microrad. The sample quality being necessary to enable the
experimental investigation of the 2D melting scenario, 2D crystallization, and
the 2D glass transition, is discussed.Comment: 13 pages, 11 figure
Guidelines for farmers, transporters and official veterinarians to assess the fitness for transport and slaughter of slaughter pigs
Legislative provisions related to animal transport and ante-mortem meat inspection of farm animals exist both at national and at European level. The Regulation (EC) No. 1/2005 characterizes the transport criteria that are to be met with regard to the animals’ health and welfare
New attempts to understand nanodiamond stardust
We report on a concerted effort aimed at understanding the origin and history
of the pre-solar nanodiamonds in meteorites including the astrophysical sources
of the observed isotopic abundance signatures. This includes measurement of
light elements by secondary ion mass spectrometry (SIMS), analysis of
additional heavy trace elements by accelerator mass spectrometry (AMS) and
dynamic calculations of r-process nucleosynthesis with updated nuclear
properties. Results obtained indicate: a) there is no evidence for the former
presence of now extinct 26Al and 44Ti in our diamond samples other than what
can be attributed to silicon carbide and other "impurities"; this does not
offer support for a supernova (SN) origin but neither does it negate it; b)
analysis by AMS of platinum in "bulk diamond" yields an overabundance of r-only
198Pt that at face value seems more consistent with the neutron burst than with
the separation model for the origin of heavy trace elements in the diamonds,
although this conclusion is not firm given analytical uncertainties; c) if the
Xe-H pattern was established by an unadulterated r-process, it must have been a
strong variant of the main r-process, which possibly could also account for the
new observations in platinum.Comment: Workshop on Astronomy with Radioactvities VII; Publications of the
Astronomical Society of Australia, accepte
Novel method to study neutron capture of U 235 and U 238 simultaneously at keV energies
The neutron capture cross sections of the main uranium isotopes, U235 and U238, were measured simultaneously for keV energies, for the first time by combining activation technique and atom counting of the reaction products using accelerator mass spectrometry. New data, with a precision of 3%-5%, were obtained from mg-sized natural uranium samples for neutron energies with an equivalent Maxwell-Boltzmann distribution of kT∼25keV and for a broad energy distribution peaking at 426 keV. The cross-section ratio of U235(n,γ)/U238(n,γ) can be deduced in accelerator mass spectrometry directly from the atom ratio of the reaction products U236/U239, independent of any fluence normalization. Our results confirm the values at the lower band of existing data. They serve as important anchor points to resolve present discrepancies in nuclear data libraries as well as for the normalization of cross-section data used in the nuclear astrophysics community for s-process studies
The s Process: Nuclear Physics, Stellar Models, Observations
Nucleosynthesis in the s process takes place in the He burning layers of low
mass AGB stars and during the He and C burning phases of massive stars. The s
process contributes about half of the element abundances between Cu and Bi in
solar system material. Depending on stellar mass and metallicity the resulting
s-abundance patterns exhibit characteristic features, which provide
comprehensive information for our understanding of the stellar life cycle and
for the chemical evolution of galaxies. The rapidly growing body of detailed
abundance observations, in particular for AGB and post-AGB stars, for objects
in binary systems, and for the very faint metal-poor population represents
exciting challenges and constraints for stellar model calculations. Based on
updated and improved nuclear physics data for the s-process reaction network,
current models are aiming at ab initio solution for the stellar physics related
to convection and mixing processes. Progress in the intimately related areas of
observations, nuclear and atomic physics, and stellar modeling is reviewed and
the corresponding interplay is illustrated by the general abundance patterns of
the elements beyond iron and by the effect of sensitive branching points along
the s-process path. The strong variations of the s-process efficiency with
metallicity bear also interesting consequences for Galactic chemical evolution.Comment: 53 pages, 20 figures, 3 tables; Reviews of Modern Physics, accepte
Robot companions for citizens
This paper describes the scientific vision and objectives of the FET Flagship candidate initiative Robot Companions for Citizens. Robot Companions will be a new generation of machines that will primarily help and assist elderly people in activities of daily living in their workplace, home and in society. They will be the ICT solution for a new sustainable welfare
Nuclear Physics Experiments with Ion Storage Rings
In the last two decades a number of nuclear structure and astrophysics
experiments were performed at heavy-ion storage rings employing unique
experimental conditions offered by such machines. Furthermore, building on the
experience gained at the two facilities presently in operation, several new
storage ring projects were launched worldwide. This contribution is intended to
provide a brief review of the fast growing field of nuclear structure and
astrophysics research at storage rings.Comment: XVIth International Conference on Electro-Magnetic Isotope Separators
and Techniques Related to their Applications, December 2--7, 2012 at Matsue,
Japa
Measurement of the stellar Ni 58 (n,γ) Ni 59 cross section with accelerator mass spectrometry
The Ni58(n,γ)Ni59 cross section was measured with a combination of the activation technique and accelerator mass spectrometry (AMS). The neutron activations were performed at the Karlsruhe 3.7 MV Van de Graaff accelerator using the quasistellar neutron spectrum at kT=25 keV produced by the Li7(p,n)Be7 reaction. The subsequent AMS measurements were carried out at the 14 MV tandem accelerator of the Maier-Leibnitz Laboratory in Garching using the gas-filled analyzing magnet system (GAMS). Three individual samples were measured, yielding a Maxwellian-averaged cross section at kT=30 keV of (σ)30keV = 30.4 (23)syst(9)stat mbarn. This value is slightly lower than two recently published measurements using the time-of-flight (TOF) method, but agrees within the uncertainties. Our new results also resolve the large discrepancy between older TOF measurements and our previous value
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