38,246 research outputs found
Farm-level data integration: future problems and consequences for public and private structures
One of the outcomes of the EC-FP7 project âFuture Farmâ was showing the need of INTEGRATION, something that PROGIS has been doing for 15 years. Within the whole sector agricultureâforestry-environment-risk management there is an enormous need for integration that is not available yet, because of on side the existing admin-sector-structures plus on the other side diverse public and/or private interests with opposite directions and in many cases the not streamlined interest of ALL involved parties. On the other hand we have the nature that is fully integrated and should be managed by us! Nothing happens without being related to something else within the nature. We have to be more aware of this and have also to understand that ICT will be the driver of integration as data and based on it these information is necessary and urgently needed for public and for private structures. We can do it separately, doing things in parallel and multiple times with multiple costs and reduced results. The other option is to cooperate on an integrative model!Commons, farm management, valuation of land, ICT, Farm Management,
Can Dark Matter Annihilation Dominate the Extragalactic Gamma-Ray Background?
Annihilating dark matter (DM) has been discussed as a possible source of
gamma-rays from the galactic center (GC) and contributing to the extragalactic
gamma-ray background (EGB). Assuming universality of the density profile of DM
halos, we show that it is quite unlikely that DM annihilation is a main
constituent of EGB, without exceeding the observed gamma-ray flux from the GC.
This argument becomes stronger when we include enhancement of the density
profiles by supermassive black holes or baryon cooling. The presence of
substructure may loosen the constraint, but only if a very large cross section
as well as the rather flat profile are realized.Comment: 4 pages, 2 figures, accepted by PR
Chargino Production and Decay in Photon-Photon-Collisions
We discuss the pair production of charginos in collisions of polarized
photons , () and the
subsequent leptonic decay of the lighter chargino including the complete spin correlations.
Analytical formulae are given for the polarization and the spin-spin
correlations of the charginos. Since the production is a pure QED process the
decay dynamics can be studied separately. For high energy photons from Compton
backscattering of polarized laser pulses off polarized electron beams numerical
results are presented for the cross section, the angular distribution and the
forward-backward asymmetry of the decay positron. Finally we study the
dependence on the gaugino mass parameter and on the sneutrino mass for a
gaugino-like MSSM scenario.Comment: 22 pages, 15 figures, version to be published in Eur. Phys. J.
Detailed stratigraphic correlation of the Neogene sedimentary sequences on the Ontong Java Plateau by well logging; ODP Sites 803, 805, 806, 807, and DSDP Site 586
We used well logs, in some cases combined with shipboard physical properties measurements to make more complete profiles and to correlate between sites on the Ontong Java Plateau. By comparing sediment bulk density, velocity, and resistivity logs from adjacent holes at the same site, we showed that even subtle features of the well logs are reproducible and are caused by variations in sedimentation. With only minor amounts of biostratigraphic information, we could readily correlate these sedimentary features across the entire top of the Ontong Java Plateau, demonstrating that for most of the Neogene the top of the plateau is a single sedimentary province. We found it more difficult, but still possible, to correlate in detail sites from the top of the plateau to those drilled on the flanks. The pattern of sedimentation rate variation down the flank of the plateau cannot be interpreted as simply controlled by dissolution. Site 805, in particular, oscillates between accumulating sediment at roughly the same rate as cores on top of the Ontong Java Plateau, and accumulating sediment as slowly as Site 803, 200 m deeper in the water column. These oscillations do not match earlier reconstructions of central Pacific carbonate compensation depth variations
Multiple H-Rearrangements in 10-Benzylthio-dithranol Radical Cations
10-Alkylthio- and 10-arylthio-derivatives of dithranol (anthralin;
1,8-dihydroxy-9-anthrone) are of interest in search for new anti-psoriatic
agents2 , 3 ). By working out ms procedures for unequivocal identification of
trace amounts of these compounds4 ) it was established that in case of
10-phenylthio-dithranol putative by-products, especially one giving rise to
ions at m/z = 226 (dithranol), are artefacts of thermal reaction in the mass
spectrometer1). In the EI-MS of those 10-substituted dithranols containing
a S-CH2R chain, however, these ions (m/z = 226) arise from M + * as well.
Scope and mechanism of their formation was examined by analyzing
compound 1 and its D-labelled derivatives 2 and 3
Distribution of carbonate in surface sediments of the Pacific Ocean
The distribution of carbonate on the floor of the Pacific has been remapped on the basis of 1313 points from 80 references stored in the World Ocean Sediment Data Bank of Scripps Institution of Oceanography. Percent distribution maps and carbonate versus depth diagrams generally agree with previously published information and reflect the major controlling factors of carbonate sedimentation (depth, hydrography, fertility, and sedimentary processes). While carbonate distributions are of limited use in attempting to construct dissolution profiles, major trends are identifiable. In particular, the degree of lowering of the equatorial calcite compensation depth (CCD) together with an estimate of the differences in supply rates between the equator and the subtropical gyre can be used to estimate dissolution rate increase below the lysocline. There is considerable variation in the sharpness of the âCCD transitionâ a concept defined here. This variation is thought to reflect both geographic differences in dissolution rate gradients and redeposition processes (carbonate, deep-sea sediments, calcite, and compensation depth)
Kinetics of silicide formation by thin films of V on Si and SiO_2 substrates
The reaction rate of vacuumâevaporated films of V of the order of 1000 Ă
thick is investigated by MeV He backscattering spectrometry. On substrates of singleâcrystal Si and for anneal times up to several hours in the temperature range 570â650°C, VSi_2 is formed at a linear rate in time. The activation energy of the process is 1.7±0.2 eV. The presence of oxygen in amounts of 10% can significantly decelerate the reaction. On substrates of SiO_2 in the temperature range 730â820°C and anneal times of several hours or less, V_3Si is formed at a squareâroot rate in time. The activation energy of this process is 2.0±0.2 eV
Chelate-modified polymers for atmospheric gas chromatography
Chromatographic materials were developed to serve as the stationary phase of columns used in the separation of atmospheric gases. These materials consist of a crosslinked porous polymer matrix, e.g., a divinylbenzene polymer, into which has been embedded an inorganic complexed ion such as N,N'-ethylene-bis-(acetylacetoniminato)-cobalt (2). Organic nitrogenous bases, such as pyridine, may be incorporated into the chelate polymer complexes to increase their chromatographic utility. With such materials, the process of gas chromatography is greatly simplified, especially in terms of time and quantity of material needed for a gas separation
Determination of the Gaugino Mass Parameter M_1 in Different Linear Collider Modes
We study the different linear collider modes with regard to the determination
of the gaugino mass parameter M_1. In a specific mSUGRA inspired scenario we
compare four processes with polarized beams: (a) e+ e- --> neutralino_1
neutralino_2 --> neutralino_1 neutralino_1 e+ e-, (b) e- gamma --> neutralino_1
selectron_{L/R} --> neutralino_1 neutralino_1 e-, (c) gamma gamma -->
chargino_1^+ chargino_1^- --> neutralino_1 neutralino_1 e+ e- neutrino_e
anti-neutrino_e, (d) e- e- --> selectron_{L/R} selectron_{L/R} --> neutralino_1
neutralino_1 e- e-.Comment: 5 pages, 8 figures, LaTex, Talk given at the 5th International Linear
Collider Workshop (LCWS 2000), Fermilab, Batavia, Illinois, Oct. 24-28, 200
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