Plastic deformation of linear polyethylene containing row structures

The mechanical and thermal properties of highly oriented polyethylene films containing shish kebab type morphology are studied. At low deformations (strain<10%) strong work hardening is observed. Higher deformations ((40%) give rise to strain softening of the material and a decrease in the Young's modulus of as much as one-third of its initial value. In addition, the high melting component of the material originating from the shish-type crystals vanishes on higher deformation. The deformation processes are discussed from the point of view of a fibre-composite material and structural changes during the deformation are followed by transmission electron microscopy.     

On the prediction of band-limited signals from past samples

A new method is used to construct coefficients a_kn such that any band-limited signal function with highest frequency ΠW can be reconstituted from its samples from the past via

$\text{?(t)=}\text{lim}\text{n→∞}\text{σ}\text{k=1}\text{n}\text{a}{}_{\mathrm{kn}}\text{?}\text{t?}\text{kT}\text{W}$

Although the existence of such predictor coefficients can be proved for each positive T < 1, so far they have been exhibited only for $\text{T ? (0,}\text{built1}\text{2}\text{)}$ by J. L. Brown, Jr. [1]. Using the mathematical tool of power series expansions in the complex domain, T can be extended to at least $\text{T <}\text{1}\text{2}$, that is, the sampling rate has to exceed three-halves the Nyquist rate. Again the predictor coefficients a_kn do not depend on the structure of ? or on the bandwidth parameter W.     

High Order Finite Difference Approximations of Electromagnetic Wave Propagation Close to Material Discontinuities

Electromagnetic wave propagation close to a material discontinuity is simulated by using summation by part operators of second, fourth and sixth order accuracy. The interface conditions at the discontinuity are imposed by the simultaneous approximation term procedure. Stability is shown and the order of accuracy is verified numerically.     

Transparent, conductive graphene electrodes for dye-sensitized solar cells

Transparent, conductive, and ultrathin graphene films, as an alternative to the ubiquitously employed metal oxides window electrodes for solid-state dye-sensitized solar cells, are demonstrated. These graphene films are fabricated from exfoliated graphite oxide, followed by thermal reduction. The obtained films exhibit a high conductivity of 550 S/cm and a transparency of more than 70% over 1000-3000 nm. Furthermore, they show high chemical and thermal stabilities as well as an ultrasmooth surface with tunable wettability.     

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