4,000 research outputs found
New Results on the Electroproduction Cross Sections off Protons
In these proceedings we present preliminary
electroproduction cross sections off protons in the kinematical area of 1.4 GeV
1.8 GeV and 0.4 GeV GeV. Our results extend
the kinematical coverage for this exclusive channel with respect to previous
measurements. Furthermore, the electroproduction cross
sections were obtained for -bins of much smaller size. The future analysis
of this data within the framework of the JLAB-MSU reaction model (JM) will
considerably improve our knowledge on the evolution of the transition
electrocouplings, in particular for the resonances with masses
above 1.6 GeV.Comment: Will be published in proceedings of NSTAR 2011 conference. 4 pages, 4
figure
Non-homogeneous random walks, subdiffusive migration of cells and anomalous chemotaxis
This paper is concerned with a non-homogeneous in space and non-local in time
random walk model for anomalous subdiffusive transport of cells. Starting with
a Markov model involving a structured probability density function, we derive
the non-local in time master equation and fractional equation for the
probability of cell position. We show the structural instability of fractional
subdiffusive equation with respect to the partial variations of anomalous
exponent. We find the criteria under which the anomalous aggregation of cells
takes place in the semi-infinite domain.Comment: 18 pages, accepted for publicatio
Trapped mode resonances in metalo-dielectric structures with electric asymmetry materials
This paper investigates the possibility of exciting high quality trapped resonant modes on frequency selective surfaces consisting of identical sub-wavelength metallic inclusions (symmetrically split rings) with no structural asymmetry but exhibitting electrical asymmetry. The electrical symmetry is broken by using different dielectric substrates. The existence of such anti-symmetric trapped mode on geometrical symmetric structure is demonstrated through numerical simulation. Numerical results suggest that the high quality factor observed for these resonant modes is achieved via weak coupling between the "trapped modes" and free space which enables the excitation of these modes
Elliptical dichroism: operating principle of planar chiral metamaterials
We employ a homogenization technique based on the Lorentz electronic theory
to show that planar chiral structures (PCSs) can be described by an effective
dielectric tensor similar to that of biaxial elliptically dichroic crystals.
Such a crystal is shown to behave like a PCS insofar as it exhibits its
characteristic optical properties, namely, co-rotating elliptical polarization
eigenstates and asymmetric, direction-dependent transmission for
left/right-handed incident wave polarization.Comment: 3 pages, version as accepted in Optics Letters but before final
shortening
Modeling of wave distribution in layered inhomogeneous environment containing a flux of discrete inhomogeneities
The algorithm of modeling wave distribution in layered random environment containing a stream of discrete inhomogeneities has been developed and realized. Dependences of dispersed and absorbed signal energies on the parameters describing inhomogeneous structure of random layered environment and inhomogeneity flux were investigated. Numerical calculations of angular spectrum of dispersed signal were carried out. Frequency spectrum of a signal passed through the flux of discrete inhomogeneities was analyze
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