adhesion of functional layer on polymeric substrates for optoelectronic applications

The use of plastic film substrates for organic electronic devices promises to enable new applications, such as flexible displays. Plastic substrates have several distinct advantages, such as ruggedness, robustness, ultra lightness, conformability and impact resistance over glass substrates, which are primarily used in flat panel displays (FPDs) today. However, high transparency, proper surface roughness, low gas permeability and high transparent electrode conductivity of the plastic substrate are required for commercial applications. Polyesters, both amorphous and semicrystalline, are a promising class of commercial polymer for optoelectronic applications. Surface modification of polyester films was performed via chemical solution determining hydrolysis or oxidation. Hydrolysis was carried out by means of sodium hydroxide solution and oxidation by using standard clean 1 (SC-1) of RCA procedure [1]. For this work we have used commercial polymer films of 100µm in thickness: AryLite™ [2], supplied by Ferrania Imaging Technologies S.p.A. and characterised by very high glass transition temperature, Mylar™ (Polyethylene Terephthalate PET) and Teonex™ (Polyethylene Naphthalate PEN) both supplied by Dupont. More over, a bioriented and semicrystalline PET have been used. The aim of this study is modifying the polymer surface to improve the adhesion between organic-inorganic layer. It was found that the NaOH and SC-1 treatment cause a decrease of contact angles. In the present study we have deposited a thin films of amorphous hydrogenated silicon (a-Si:H) and its oxide (SiO2) on a new high temperature polymer substrate, AryLite™, by plasma enhanced chemical vapour deposition (PECVD) [3], with a radio frequency plasma system

Lateral load effects on tall shear wall structures of different height

A three-dimensional formulation is proposed to analyze the lateral loading distribution of external actions in high-rise buildings. The method is extended to encompass any combination of bracings, including bracings with open thin-walled cross-sections, which are analyzed in the framework of Timoshenko-Vlasov’s theory of sectorial areas. More in detail, the proposed unified approach is a tool for the preliminary stages of structural design. It considers infinitely rigid floors in their own planes, and allows to better understand stress and strain distributions in the different bearing elements if compared to a finite element analysis. Numerical examples, describing the structural response of tall buildings characterized by bracings with different cross-section and height, show the effectiveness and flexibility of the proposed method. The accuracy of the results is investigated by a comparison with finite element solutions, in which the bracings are modelled as three-dimensional structures by means of shell elements

State prediction of an entropy wave advecting through a turbulent channel flow

Survival of entropy waves during their advection throughout a combustor is central to the generation of entropic sound and the subsequent effects upon thermoacoustic stability of the system. However, the decay and spatial non-uniformity of entropy waves are largely ignored by the existing models used for the calculation of entropy noise generation. Recent investigations have demonstrated the complex spatio-temporal dynamics of entropy waves and cast doubts on the sufficiency of the one-dimensional approach, conventionally used for the analysis of these waves. Hence, this paper proposes a novel approach to the low-order modelling of entropy wave evolution wherein the wave is described by the two states of position and amplitude in the streamwise direction. A high-order model is first developed through direct numerical simulation of the advection of entropy waves in a fully developed, heat transferring, compressible, turbulent channel flow. The data are then utilised to build and validate a series of nonlinear, low-order models that provide an unsteady two-dimensional representation of the decaying and partially annihilating entropy waves. It is shown that these models need, at most, approximately of the total trace of entropy wave advection to predict the wave dynamics accurately. The results further reveal that the existing linear low-order models are truly predictive only for the entropy waves with less than increase in the gas temperature compared to that of the surrounding flow. Yet, in agreement with the assumption of existing models, it is shown that entropy waves travel with the mean flow speed

Progressive Transient Photon Beams

In this work we introduce a novel algorithm for transient rendering in participating media. Our method is consistent, robust, and is able to generate animations of time-resolved light transport featuring complex caustic light paths in media. We base our method on the observation that the spatial continuity provides an increased coverage of the temporal domain, and generalize photon beams to transient-state. We extend the beam steady-state radiance estimates to include the temporal domain. Then, we develop a progressive version of spatio-temporal density estimations, that converges to the correct solution with finite memory requirements by iteratively averaging several realizations of independent renders with a progressively reduced kernel bandwidth. We derive the optimal convergence rates accounting for space and time kernels, and demonstrate our method against previous consistent transient rendering methods for participating media

Shear-Velocity Structure and Dynamics Beneath the Sicily Channel and Surrounding Regions of the Central Mediterranean Inferred From Seismic Surface Waves

The evolution of the Sicily Channel Rift Zone (SCRZ) is thought to accommodate the regional tectonic stresses of the Calabrian subduction system. Much of the observations we have today are either limited to the surface or to the upper crust or deeper from regional seismic tomography, missing important details about the lithospheric structure and dynamics. It is unclear whether the rifting is passive from far-field extensional stresses or active from mantle upwelling beneath. We measure Rayleigh-and Love-wave phase velocities from ambient seismic noise and invert for 3-D shear-velocity and radial anisotropic models. Variations in crustal S-velocities coincide with topographic and tectonic features. The Tyrrhenian Sea has a ∼10 km thin crust, followed by the SCRZ (∼20 km). The thickest crust is beneath the Apennine-Maghrebian Mountains (∼55 km). Areas experiencing extension and intraplate volcanism have positive crustal radial anisotropy (VSH > VSV); areas experiencing compression and subduction-related volcanism have negative anisotropy. The crustal anisotropy across the Channel shows the extent of the extension. Beneath the Tyrrhenian Sea, we find very low sub-Moho S-velocities. In contrast, the SCRZ has a thin mantle lithosphere underlain by a low-velocity zone. The lithosphere-asthenosphere boundary rises from 60 km depth beneath Tunisia to ∼33 km beneath the SCRZ. Negative radial anisotropy in the upper mantle beneath the SCRZ is consistent with vertical mantle flow. We hypothesize a more active mantle upwelling beneath the rift than previously thought from an interplay between poloidal and toroidal fluxes related to the Calabrian slab, which in turn produces uplift at the surface and induces volcanism

Obesity as a social phenomenon: A narrative review

BACKGROUND: obesity is one of the most prevalent diseases all over the world. Because of its high social impact, the broadest possible approach on several levels - and not limited only to clinical aspect - is needed to better understand and face the challenges obesity poses to public health. OBJECTIVES: to analyse, through the main evidence, the so- cial impact of weight excess in the general population and the actions aimed at mitigating its negative effects. DESIGN: narrative review. SETTING: data obtained from the sources included in the study were gathered and analyzed in five macroareas: Health Inequality, Society, Work, Impact on Social Medicine (focused on the Italian model), and Social Costs. RESULTS: each category showed a bilateral relationship with obesity having a significant impact for the community. CONCLUSIONS: for each field, various actions should be taken at institutional level. Many recommendations and actions have already been taken worldwide, but they alone seem to be not enough. This work points out that, in order to combat obesity and bring about a slowdown of this pandemic, the en- tire scientific community and institutions must work together to identify and design programmes that are truly effective