13,959 research outputs found
Task 4 completion report for 40 Kilowatt grid connected modification contract
Startup, operation in grid connect mode, shutdown from grid connects, operation in isolated mode, shutdown from isolated mode, steady state operation, mode transfers, and voltage disconnects are addressed
Shadowing and Absorption Effects on J/psi Production in dA Collisions
We study medium modifications of J/psi production in cold nuclear media in
deuterium-nucleus collisions. We discuss several parameterizations of the
modifications of the parton densities in the nucleus, known as shadowing, an
initial-state effect. We also include absorption of the produced J/psi by
nucleons, a final-state effect. Both spatially homogeneous and inhomogeneous
shadowing and absorption are considered. We use the number of binary
nucleon-nucleon collisions as a centrality measure. Results are presented for
d+Au collisions at sqrt{S_{NN}} = 200 GeV and for d+Pb collisions at
sqrt{S_{NN}} = 6.2 TeV. To contrast the centrality dependence in pA and dA
collisions, we also present pPb results at sqrt{S_{NN}} = 8.8 TeV.Comment: 22 pages, 11 figures, uses revte
Bait sprays against the European cherry fruit fly Rhagoletis cerasi: Status Quo & Perspectives
Bait spray experiments against Rhagoletis cerasi were carried out in 2005 to 2007. The
main principle of this method is to use food (e.g. sugar and proteins) as baits for the flies
with small amounts of insecticides, which is applied on parts of the cherry tree. Main focus
was aimed at laboratory and field cage experiments using the commercial GF-120
Naturalyte Fruit Fly BaitTM with the insecticide spinosad, which is registered against North
American cherry fruit fly species in the US and Canada. Furthermore, additional bait spray
formulations as alternatives to GF-120 were used to define the right food bait quality for a
high attractiveness and low reproduction ability. Beyond, the negative effect on
reproduction of flies for azadirachtin (neem) was shown. During this project, promising
results, e.g. efficacies up to 99 % with infestation rates below the infestation threshold
were obtained. From 2008 on, other insecticides, like azadirachtin (neem) and pyrethrine
in an appropriate food bait mixture will be used. Questions like efficacy, adequate
concentrations, persistence, rainfastness and practicability in commercial cherry orchards
will be answered
Depinning of disordered bosonic chains
We consider one-dimensional bosonic chains with a repulsive boson-boson
interaction that decays exponentially on large length-scales. This model
describes transport of Cooper-pairs in a Josepshon junction array, or transport
of magnetic flux quanta in quantum-phase-slip ladders, i.e. arrays of
superconducting wires in a ladder-configuration that allow for the coherent
tunnelling of flux quanta. In the low-frequency, long wave-length regime these
chains can be mapped to an effective model of a one-dimensional elastic field
in a disordered potential. The onset of transport in these systems, when biased
by external voltage, is described by the standard depinning theory of elastic
media in disordered pinning potentials. We numerically study the regimes that
are of relevance for quantum-phase-slip ladders. These are (i) very short
chains and (ii) the regime of weak disorder. For chains shorter than the
typical pinning length, i.e., the Larkin length, the chains reach a saturation
regime where the depinning voltage does not depend on the decay length of the
repulsive interaction. In the regime of weak disorder we find an emergent
correlation length-scale that depends on the disorder strength. For arrays
shorter than this length the onset of transport is similar to the clean arrays,
i.e., is due to the penetration of solitons into the array. We discuss the
depinning scenarios for longer arrays in this regime.Comment: 11 pages, 6 figure
Influence of two-level fluctuators on adiabatic passage techniques
We study the process of Stimulated Raman Adiabatic Passage (STIRAP) under the
influence of a non-trivial solid-state environment, particularly the effect of
two-level fluctuators (TLFs) as they are frequently present in solid-state
devices. When the amplitudes of the driving-pulses used in STIRAP are in
resonance with the level spacing of the fluctuators the quality of the
protocol, i.e., the transferred population decreases sharply. In general the
effect can not be reduced by speeding up the STIRAP process. We also discuss
the effect of a structured noise environment on the process of Coherent
Tunneling by Adiabatic Passage (CTAP). The effect of a weakly structured
environment or TLFs with short coherence times on STIRAP and CTAP can be
described by the Bloch-Redfield theory. For a strongly structured environment a
higher-dimensional approach must be used, where the TLFs are treated as part of
the system.Comment: 8 pages, 8 figure
Congener specific analysis of polychlorinated terphenyls
In order to identify and to quantify polychlorinated terphenyls (PCT) in environmental matrices, the chro-
matographic behavior of coplanar and non-coplanar congeners was evaluated. A mixture of 16 single PCT
congeners was used for method development. Four of these compounds were synthesized for the first
time by SUZUKI-coupling reaction. These were p-PCT (2,200
,6,600
-tetrachloro-, 20
,3,300
,4,400
,50
,-hexachloro-,
20
,3,300
,5,50
,500
-hexachloro-) and m-PCT (2,200
,3,300
,5,500
-hexachloro-). They were characterized by NMR
(
1
H,
13
C) spectroscopy. By means of the new column chromatographic clean-up reported here, a good
matrix removal and the separation of the coplanar PCT congeners from the non-coplanar ones was
obtained. The recovery rates for all congeners were good for the PCT in different test matrices like fat,
charcoal, and soil. The quality of the clean-up, the separation and the recovery rates were determined
by GC/MS analysis. The method was applied for the first time to a real sample from a fire accident, where
different PCT, obviously formed during the combustion process, were found. The conclusion is drawn that
this method is suitable for the analysis of PCT in different environmental samples
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