Distribution of major,minor and trace elements in Antarctic offshore and Coastal seawaters: correlation among sites and variables by pattern recognition

The composition of seawater in the Ross Sea (Antarctica) was investigated. The distribution of heavy metals (Cd, Cu, Fe, Mn, Ni), minor and trace (B, Ba, Li, Sr, Si) and major (Na, K, Ca, Mg) elements in coastal and offshore sites was determined. The samples were collected during the XIII Campaign of the Italian “National Programme of Research in Antarctica”, PNRA, at different depths and different stages of the Antarctic summer. In the subsequent campaign the concentrations in the water top micro-layer, and just below it, were compared. Results are also given for the data treatment by pattern recognition.     

Generalized retarded integral inequalities

We prove some new retarded integral inequalities. The results generalize those in [Y.G. Sun, On retarded integral inequalities and their applications, J. Math. Anal. Appl. 301 (2) (2005) 265–275].     

Ferroelectric PbTiO3 nanostructures onto Si-based substrates with size and shape control

A bottom-up approach based on the use of a microemulsion-assisted chemical solution deposition method, previously developed for the fabrication of PbTiO₃ nanostructures onto single crystal SrTiO₃ substrates, is used here on polycrystalline Pt/Si-based substrates, aiming at their integration with the current microelectronics technology. This bottom-up approach not only does not produce any damage to the nanostructures, thus not affecting noticeably their ferroelectric properties, but also solves some of the problems associated to those approaches that use the microstructural instability of ultrathin films, where islands with different shapes and sizes (single or bimodal log-normal distributions) are obtained. In this case, normal (Gaussian) size distributions are obtained, with average lateral sizes of ~70 nm, weakly depending on the solution concentration. These results show that the growth process of the nanoparticles takes place independently from one another inside the isolated micelles of the precursor solution, whose shape and size distribution therefore control effectively those of the PbTiO₃ nanostructures.     

Combined dynamic Grüss inequalities on time scales

We prove a more general version of the Grüss inequality by using the recent theory of combined dynamic derivatives on time scales and the more general notions of diamond-α derivative and integral. For the particular case where α = 1, one obtains the delta-integral Grüss inequality on time scales in (see M. Bohner and T. Matthews [5]); for α = 0 a nabla-integral Grüss inequality is derived. If we further restrict ourselves by fixing the time scale to the real (or integer) numbers, then the standard continuous (discrete) inequalities are obtained.     

Trocknen von Gasen

Ohne Zusammenfassung     

Quantitative assessment of lateral resolution improvement in digital holography

Controllable experimental features such as wavelength, camera’s specifications and reconstruction distance, determine the theoretical limit for lateral resolution in digital holography; however, due to the speckle noise associated to any coherent imaging system it is not possible to reach this theoretical limit. In this paper, a quantitative study the lateral resolution for digital holography under the effect the speckle noise is carried out. It is shown that by reducing the contrast of the speckle noise the resolution capabilities of digital holography are improved; the signal-to-noise ratio of the reconstructed holograms is the metric use to quantitatively assess the reached resolution in the holographic experiments.     

Perfect simulation for locally continuous chains of infinite order

We establish sufficient conditions for perfect simulation of chains of infinite order on a countable alphabet. The new assumption, localized continuity, is formalized with the help of the notion of context trees, and includes the traditional continuous case, probabilistic context trees and discontinuous kernels. Since our assumptions are more refined than uniform continuity, our algorithms perfectly simulate continuous chains faster than the existing algorithms of the literature. We provide several illustrative examples.