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

Considerations concerning fatigue life of metal matrix composites

Since metal matrix composites (MMC) are composed from two very distinct materials each having their own physical and mechanical properties, it is feasible that the fatigue resistance depends on the strength of the weaker constituent. Based on this assumption, isothermal fatigue lives of several MMC's were analyzed utilizing a fatigue life diagram approach. For each MMC, the fatigue life diagram was quantified using the mechanical properties of its constituents. The fatigue life regions controlled by fiber fracture and matrix were also quantitatively defined

An investigation on the effect of driver style and driving events on energy demand of a PHEV

Environmental concerns, security of fuel supply and CO2 regulations are driving innovation in the automotive industry towards electric and hybrid electric vehicles. The fuel economy and emission performance of hybrid electric vehicles (HEVs) strongly depends on the energy management system (EMS). Prior knowledge of driving information could be used to enhance the performance of a HEV. However, how the necessary information can be obtained to use in EMS optimisation still remains a challenge. In this paper the effect of driver style and driving events like city and highway driving on plug in hybrid electric vehicle (PHEV) energy demand is studied. Using real world driving data from three drivers of very different driver style, a simulation has been exercised for a given route having city and highway driving. Driver style and driving events both affect vehicle energy demand. In both driving events considered, vehicle energy demand is different due to driver styles. The major part of city driving is reactive driving influenced by external factors and driver leading to variation in vehicle speed and hence energy demand. In free highway driving, the driver choice of cruise speed is the only factor affecting vehicle energy demand

Are there stable long-range ordered Fe(1-x)Cr(x) compounds?

The heat of formation of Fe-Cr alloys undergoes an anomalous change of sign at small Cr concentrations. This observation raises the question whether there are intermetallic phases present in this composition range. Here we report the discovery of several long-range ordered structures that represent ground state phases at zero Kelvin. In particular we have identified a structure at 3.7% Cr with an embedding energy which is 49 meV/Cr atom below the solid solution. This implies there is an effective long-range attractive interaction between Cr atoms. We propose that the structures found in this study complete the low temperature-low Cr region of the phase diagram.Comment: 3 pages, 2 figure

Doubly heavy hadrons and the domain of validity of doubly heavy diquark--anti-quark symmetry

In the limit of heavy quark masses going to infinity, a symmetry is known to emerge in QCD relating properties of hadrons with two heavy quarks to analogous states with one heavy anti-quark. A key question is whether the charm mass is heavy enough so that this symmetry is manifest in at least an approximate manner. The issue is crucial in attempting to understand the recent reports by the SELEX Collaboration of doubly charmed baryons. We argue on very general grounds that the charm quark mass is substantially too light for the symmetry to emerge automatically via colour coulombic interactions. However, the symmetry could emerge approximately depending on the dynamical details.Comment: 9 page

Large N_c confinement and turbulence

We suggest that the transition that occurs at large $N_c$ in the eigenvalue distribution of a Wilson loop may have a turbulent origin. We arrived at this conclusion by studying the complex-valued inviscid Burgers-Hopf equation that corresponds to the Makeenko-Migdal loop equation, and we demonstrate the appearance of a shock in the spectral flow of the Wilson loop eigenvalues. This picture supplements that of the Durhuus-Olesen transition with a particular realization of disorder. The critical behavior at the formation of the shock allows us to infer exponents that have been measured recently in lattice simulations by Narayanan and Neuberger in $d=2$ and $d=3$. Our analysis leads us to speculate that the universal behavior observed in these lattice simulations might be a generic feature of confinement, also in $d=4$ Yang-Mills theory.Comment: 4 pages, no figures- Some rewriting - Typos corrected - References completed and some correcte