20,751 research outputs found
Modeling 3-D objects with planar surfaces for prediction of electromagnetic scattering
Electromagnetic scattering analysis of objects at resonance is difficult because low frequency techniques are slow and computer intensive, and high frequency techniques may not be reliable. A new technique for predicting the electromagnetic backscatter from electrically conducting objects at resonance is studied. This technique is based on modeling three dimensional objects as a combination of flat plates where some of the plates are blocking the scattering from others. A cube is analyzed as a simple example. The preliminary results compare well with the Geometrical Theory of Diffraction and with measured data
Away-side azimuthal distribution in a Markovian parton scattering model
An event generator is constructed on the basis of a model of multiple
scattering of partons so that the trajectory of a parton traversing a dense and
expanding medium can be tracked. The parameters in the code are adjusted to fit
the \Delta\phi azimuthal distribution on the far side when the trigger momentum
is in the non-perturbative region, p_T(trigger)<4 GeV/c. The dip-bump structure
for 1<p_T(assoc)<2.5 GeV/c is reproduced by averaging over the exit tracks of
deflected jets. An essential characteristic of the model, called Markovian
Parton Scattering (MPS) model, is that the scattering angle is randomly
selected in the forward cone at every step of a trajectory that is divided into
many discrete steps in a semi-classical approximation of the non-perturbative
scattering process. Energy loss to the medium is converted to thermal partons
which hadronize by recombination to give rise to the pedestal under the bumps.
When extended to high trigger momentum with \pt(trigger) >8 GeV/c, the model
reproduces the single-peak structure observed by STAR without invoking any new
dynamical mechanism.Comment: 20 pages + 3 figure
Is Noncontact ACL Injury Associated with the Posterior Tibial and Meniscal Slope?
Background: The risk of noncontact ACL injury reportedly is increased in patients with a greater posterior tibial slope (PTS), but clinical data are inconsistent. It is unclear whether the medial and lateral PTSs have a different impact on this connection. It also is unknown whether the meniscal slope (MS) is associated with ACL injury. Patients/methods: Using MRI, we compared the medial and lateral PTSs and MSs separately in 55 matched pairs of patients with isolated noncontact ACL injuries and a control group. Results: Neither the PTS nor the relative difference between the medial and lateral PTSs differed between groups. In contrast, the lateral MS was greater with ACL injuries: 2.0° versus −2.7° in males with and without ACL injury and 1.7° versus −0.9 in females. Uninjured females had a greater PTS than males: 4.9° versus 3.0° in females and males medially, respectively; 5.7° versus 4.0° lateral. Conclusions: There is no obvious link between the medial or lateral PTSs and ACL injury, and there is no obvious link between the relative difference in the medial and lateral PTSs and noncontact ACL injury. However, a greater lateral MS may indicate a greater risk of injury. The PTS can differ between the genders but the average difference is small. Level of Evidence: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidenc
The chemical equilibration volume: measuring the degree of thermalization
We address the issue of the degree of equilibrium achieved in a high energy
heavy-ion collision. Specifically, we explore the consequences of incomplete
strangeness chemical equilibrium. This is achieved over a volume V of the order
of the strangeness correlation length and is assumed to be smaller than the
freeze-out volume. Probability distributions of strange hadrons emanating from
the system are computed for varying sizes of V and simple experimental
observables based on these are proposed. Measurements of such observables may
be used to estimate V and as a result the degree of strangeness chemical
equilibration achieved. This sets a lower bound on the degree of kinetic
equilibrium. We also point out that a determination of two-body correlations or
second moments of the distributions are not sufficient for this estimation.Comment: 16 pages, 15 figures, revtex
Renormalization group improved black hole space-time in large extra dimensions
By taking into account a running of the gravitational coupling constant with
an ultra violet fixed point, an improvement of classical black hole space-times
in extra dimensions is studied. It is found that the thermodynamic properties
in this framework allow for an effective description of the black hole
evaporation process. Phenomenological consequences of this approach are
discussed and the LHC discovery potential is estimated.Comment: 13 pages, 6 figure
An Introduction to Superconducting Qubits and Circuit Quantum Electrodynamics
A subset of the concepts of circuit quantum electrodynamics are reviewed as a
reference to the Axion Dark Matter Experiment (ADMX) community as part of the
proceedings of the 2nd Workshop on Microwave Cavities and Detectors for Axion
Research. The classical Lagrangians and Hamiltonians for an LC circuit are
discussed along with black box circuit quantization methods for a weakly
anharmonic qubit coupled to a resonator or cavity
Dynamical scaling of the quantum Hall plateau transition
Using different experimental techniques we examine the dynamical scaling of
the quantum Hall plateau transition in a frequency range f = 0.1-55 GHz. We
present a scheme that allows for a simultaneous scaling analysis of these
experiments and all other data in literature. We observe a universal scaling
function with an exponent kappa = 0.5 +/- 0.1, yielding a dynamical exponent z
= 0.9 +/- 0.2.Comment: v2: Length shortened to fulfil Journal criteri
Entwicklung und Darstellung von Strategieoptionen zur Behandlung von Saatgut im ökologischen Landbau
Zur Erzeugung gesunden Saatgutes steht im Öko-Landbau neben präventiven Maßnahmen eine Reihe verschiedener Saatgutbehandlungsverfahren zur Verfügung (physikalische Methoden, Pflanzenextrakte, Naturstoffe und Mikroorganismenpräparate), die jedoch für die zahlreichen, wichtigen Wirt/Pathogen-Kombinationen nicht hinreichend untersucht waren. Inhalt und Ziel dieses Verbundvorhabens war es, Erfolg versprechende, aber hinsichtlich Handhabbarkeit und Wirksamkeit bislang nicht ausreichend untersuchte Varianten zu überprüfen sowie Schwellenwerte zu ermitteln, die eine Saatgutbehandlung indizieren.
Um eine schnelle Übertragbarkeit wirksamer Verfahren in die Praxis zu ermöglichen, wurden neben den physikalischen Verfahren überwiegend gelistete Pflanzenstärkungsmittel untersucht.
Im ersten Untersuchungsschritt wurden Klimakammer- und Gewächshausversuche angelegt. Ansätze, die sich unter diesen Modellbedingungen für die Praxistestung als geeignet erwiesen, wurden in Feldversuchen (Projekt 03OE127/2) überprüft.
Für wichtige Wirt/Pathogen-Kombinationen konnten unter Modellbedingungen Behandlungsvarianten mit guten Wirkungen ausgewählt werden, die keine bis geringe negative Auswirkungen auf die Keimfähigkeit hatten. Bei Sommergerste mit Netzflecken oder Streifenkrankheit sowie bei Haferflugbrand konnten nach Behandlung mit Heißwasser, LEBERMOOSER, Ethanol, Milsana flüssig, Serenade und/oder Cedomon gute bis sehr gute Wirkungen erreicht werden. An Winterweizen mit Fusarium spp., Stagonospora nodorum bzw. Schneeschimmel sowie Winterroggen mit Schneeschimmel wurde eine Wirkung vor allem durch FZB 53, Warm- oder Heißwasserbehandlung und LEBERMOOSER erreicht.
Von den besonders schwer zu bekämpfenden Krankheiten wurden Anthraknose an Lupine und Ascochyta pisi an Erbse mit Feuchtheißluft reduziert, jedoch war die Wirkung nicht ausreichend
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