Broad distribution effects in sums of lognormal random variables

The lognormal distribution describing, e.g., exponentials of Gaussian random variables is one of the most common statistical distributions in physics. It can exhibit features of broad distributions that imply qualitative departure from the usual statistical scaling associated to narrow distributions. Approximate formulae are derived for the typical sums of lognormal random variables. The validity of these formulae is numerically checked and the physical consequences, e.g., for the current flowing through small tunnel junctions, are pointed out.Comment: 14 pages, 9 figures. Minor changes + Gini coefficient and 4 refs. adde

Noise-assisted Thouless pump in elastically deformable molecular junctions

We study a Thouless pump realized with an elastically \textit{deformable quantum dot} whose center of mass follows a non-linear stochastic dynamics. The interplay of noise, non-linear effects, dissipation and interaction with an external time-dependent driving on the pumped charge is fully analyzed. The results show that the quantum pumping mechanism not only is not destroyed by the force fluctuations, but it becomes stronger when the forcing signal frequency is tuned close to the resonance of the vibrational mode. The robustness of the quantum pump with temperature is also investigated and an exponential decay of the pumped charge is found when the coupling to the vibrational mode is present. Implications of our results for nano-electromechanical systems are also discussed.Comment: 2 Appendices and figures adde

Gingival hyperplasia around dental implants in jaws reconstructed with free vascularized flaps: a case report series

Free vascularized flaps are the gold standard for reconstruction of the facial skeleton after surgical ablation of pathologies or when important atrophy of the jaws exists. A frequent problem seen during prosthetic rehabilitation after reconstruction with free vascularized flaps is the onset of hyperplastic granulomatous reactive tissue around the prosthetic abutment of the implant. The features of this phenomenon seem to be directly related to the characteristics of the periimplant tissue and of the manufacturing materials of the prosthesis and abutments. This complication can be seen quite often; we found it in 7 of 40 patients (17.5%). It does not seem to significantly affect the survival rate of implants. The aim of the study was to analyze the behavior of such lesions and to suggest our clinical approach with the management of these kinds of patients and complications. To remove gingival hyperplasia, we used either a traditional cold scalpel or an electric cautery or laser. We had good results using these tools. The onset of this phenomenon was not influenced by either the kind of implant and free flaps used or by the local conditions of the patients (such as radiotherapy). The number of recurrences was highly influenced by the oral hygiene of the patients

Longitudinal phase-space manipulation with beam-driven plasma wakefields

The development of compact accelerator facilities providing high-brightness beams is one of the most challenging tasks in field of next-generation compact and cost affordable particle accelerators, to be used in many fields for industrial, medical and research applications. The ability to shape the beam longitudinal phase-space, in particular, plays a key role to achieve high-peak brightness. Here we present a new approach that allows to tune the longitudinal phase-space of a high-brightness beam by means of a plasma wakefields. The electron beam passing through the plasma drives large wakefields that are used to manipulate the time-energy correlation of particles along the beam itself. We experimentally demonstrate that such solution is highly tunable by simply adjusting the density of the plasma and can be used to imprint or remove any correlation onto the beam. This is a fundamental requirement when dealing with largely time-energy correlated beams coming from future plasma accelerators

Fish community in a surf zone of the northern Sicilian coast (Mediterranean Sea): diversity and functional guild composition

Fish assemblage in a surf zone of the southern Tyrrhenian Sea was investigated for the first time. Samples were collected during four surveys by a modified beach-seine, from June 2005 to May 2006. Overall, 42 species belonging to 19 families were recorded. Among them, Sardina pilchardus showed the highest abundance values, while Mugilids (Oedalechilus labeo and Liza aurata) were the most frequently caught species. The fish community was dominated by pelagic and gregarious species using this habitat as a foraging ground and recruitment area. Juveniles and early adults made up the largest proportion of the ichthyofauna. Fishes inhabiting the surf zone were mainly strictly benthic invertebrate feeders and invertivorous/piscivorous fish; strictly planktivorous were represented by few species but strongly dominant in terms of catch per unit effort; strictly piscivorous fish were poorly represented. Fish composition varied over the study period with the greatest abundance in May and December, and the highest richness and diversity in October

Evaluation of the Casimir Force for a Dielectric-diamagnetic Cylinder with Light Velocity Conservation Condition and the Analogue of Sellmeir's Dispersion Law

We study the Casimir pressure for a dielectric-diamagnetic cylinder subject to light velocity conservation and with a dispersion law analogous to Sellmeir's rule. Similarities to and differences from the spherical case are pointed out.Comment: 19 pages Latex, no figures; discussion expanded. To appear in Physica Script

Efecto del secado y de los métodos químicos y naturales para el procesamiento de aceitunas negras Biancolilla

In the present work, the effects of different drying and brining treatments on pigmented Biancolilla olives were evaluated. The olive cultivar considered is typical of Sicily and was harvested at pigmented state. The carpological data revealed its good quality as table olives. A preliminary fermentation in brine was applied to the samples. Half of the samples were dried whereas the remaining olives were subjected to three different lye treatments and oxidation steps. After washing, the olives were stored according to a natural fermentation or drying process with or without a pretreatment of iron gluconate. The fermentation and oxidation steps conditioned the hygienic characteristics of the final product affecting the pH value of the brine. The use of iron salt for improving the darkening rate of processed olives influenced the color parameters as expected. The oxidation and the addition of iron salt affected the texture of dried olives making them softer than those directly dried. The results suggest that the Biancolilla cultivar is suitable for fermentation in brine without any previous treatment such as oxidation.En el presente trabajo se han evaluado los efectos de los diferentes tratamientos de secado y salado para aceitunas pigmentadas Biancolilla. La variedad de aceituna seleccionada es considerada la típica de Sicilia y fue cosechada en el estadío de pigmentación. Los datos morfolóficos revelan su buena calidad como aceituna de mesa. Se ha aplicado a las muestras una fermentación preliminar. La mitad de ellas se secaron, mientras que las restantes fueron sometidas a tres tratamientos diferentes con lejía y procesos oxidantes. Después del lavado, las aceitunas se almacenan mediante una fermentación natural o proceso de secado, con o sin un pretratamiento de gluconato de hierro. Los pasos de fermentación y oxidación condicionan las características higiénicas del producto final afectando al valor del pH de la salmuera. El uso de la sal de hierro para mejorar la velocidad de oscurecimiento de las aceitunas procesadas influyó sobre los parámetros del color como se esperaba. La oxidación y la adición de la sal de hierro afectó a la textura de las aceitunas secas haciéndolas más blandas que las secadas directamente. Los resultados sugieren que la variedad Biancolilla es adecuada para la fermentación en salmuera, sin ningún tratamiento, tal como la oxidación

Growth of carbonaceous nanomaterials over stainless steel foams. Effect of activation temperature

Some of the problems that occur during the operation of chemical reactors based of structured catalytic substrates, as monoliths, foams, membranes, cloths, fibres and other systems, are related to the preparation of long term stable coatings. Frequently, the deposition of the catalytic layer is carried out by washcoating, requiring this step a cautious attention, especially in the case of complex geometries, like of that of foams or cloths. In the case of the deposition of layers of carbonaceous materials (CNMs), an alternative route, avoiding the washcoating, it is their direct growth by catalytic decomposition light hydrocarbons (also called CCVD), over the surface of the metallic substrate. In this case, if the metallic substrate is of stainless steel, it already contains the catalytic active phases like Fe and Ni. In order to optimize the process of CNMs growth over structured metallic substrates, we are studying the effect of the main operational variables of the ethane decomposition reaction on stainless steel foams. In this contribution we present a study of the influence of the temperature of the activation (oxidation and reduction) stage on the type and morphology of the carbonaceous materials formed. The results obtained allow us to determine the optimal operating conditions to maximize the amount and the selectivity of the process to obtain a given type of CNM