A deeper insight into quantum state transfer from an information flux viewpoint

We use the recently introduced concept of information flux in a many-body register in order to give an alternative viewpoint on quantum state transfer in linear chains of many spins.Comment: 6 pages, 3 figures, RevTeX

Analysis and optimization of hybrid double lap aluminum-GFRP joints

In this paper a systematic investigation of the mechanical performance of hybrid double-lap Al-GFRP bonded-bolted joints, has been carried out by using experimental analyses and numerical simulations. In order to detect the optimal geometric configuration, as well as to highlight the contribution of adhesive and bolts, the results relative to hybrid joints have been compared with those of simply adhesively bonded and simply bolted joints. The experimental and numerical results have shown that by using the minimum overlap length provided from theory, the bolt leads to a significant decreasing of both the maximum shear and the maximum peel stresses in the adhesive layer and, consequently, the hybrid joint exhibits a static tensile strength that is in practice equal to the sum of the relative values corresponding to the simply bonded joint and the simply bolted joint. Moreover, the so configured hybrid joint, exhibits an energy absorption and a fatigue strength higher than twice those of the simply adhesively bonded joint that are, in turn, higher than those of the simply bolted joint. © 2014 Elsevier Ltd

NUMERICAL-EXPERIMENTAL METHOD FOR THE ANALYSIS OF RESIDUAL STRESSES IN COLD-EXPANDED HOLES

Hole cold expansion is a technique widely used to improve the fatigue life of components with holes, e.g. bolted or riveted joints. As it has been demonstrated in literature by analytical, numerical and experimental analyses carried out by several authors, the compressive residual stresses introduced by the hole cold expansion have a beneficial influence on both the static and the fatigue strength of the treated component, because they reduce significantly the typical stress peaks around the hole due to stress concentration. In the literature, various analyses of the residual stresses introduced by the hole cold expansion have been performed by using several methods such as X-ray diffraction, neutron diffraction and the modified Sachs method. Unfortunately, all these method are affected by some limitations: low measurement depth (X-ray method), complex measurement procedure (neutron diffraction method) and approximate formulation (Sachs method). In order to overcome such drawbacks, in this study a new mechanical method, based on an innovative extension of the “rectilinear groove method” associated with the classical “integral method” calculation procedure, is proposed. Experimental assessment of the proposed method has been performed by using aluminum 5083 H321 specimens with holes subjected to various levels of cold expansion

A ricardian analysis of the impact of climate change on permanent crops in a mediterranean region

This is the first study which explores the impact of climate change in Sicily, a small Mediterranean region of Southern Europe. According to research, Mediterranean area has shown large climate shifts in the last century and it has been identified as one of the most prominent “Hot-Spots” in future climate change projections. Since agriculture is an economic activity which strongly depends on climate setting and is particularly responsive to climate changes, it is important to understand how such changes may affect agricultural profitability in the Mediterranean region. The aim of the present study is to assess the expected impact of climate change on permanent crops cultivated in Sicilian region (Southern Italy). By using data from Farm Accountancy Data Network and Ensembles climatic projections for 2021-2050 period, we showed that the impact of climate change is prominent in this region. However, crops respond to climatic variations in a different manner, highlighting that unlike the strong reduction in profitability of grapevine and citrus tree, the predicted average Net Revenue of olive tree is almost the same as in the reference period (1961-1990)

Dispersal of larval and juvenile seabream: Implications for Mediterranean marine protected areas

In the marine context, information about dispersal is essential for the design of networks of marine protected areas (MPAs). Generally, most of the dispersal of demersal fishes is thought to be driven by the transport of eggs and larvae in currents, with the potential contribution of dispersal in later life stages relatively minimal.Using otolith chemistry analyses, we estimate dispersal patterns across a spatial scale of approximately 180. km at both propagule (i.e. eggs and larvae) and juvenile (i.e. between settlement and recruitment) stages of a Mediterranean coastal fishery species, the two-banded seabream Diplodus vulgaris. We detected three major natal sources of propagules replenishing local populations in the entire study area, suggesting that propagule dispersal distance extends to at least 90. km. For the juvenile stage, we detected dispersal of up to 165. km. Our work highlights the surprising and significant role of dispersal during the juvenile life stages as an important mechanism connecting populations. Such new insights are crucial for creating effective management strategies (e.g. MPAs and MPA networks) and to gain support from policymakers and stakeholders, highlighting that MPA benefits can extend well beyond MPA borders, and not only via dispersal of eggs and larvae, but also through movement by juveniles

Experimental Realization of a One-way Quantum Computer Algorithm Solving Simon's Problem

We report an experimental demonstration of a one-way implementation of a quantum algorithm solving Simon's Problem - a black box period-finding problem which has an exponential gap between the classical and quantum runtime. Using an all-optical setup and modifying the bases of single-qubit measurements on a five-qubit cluster state, key representative functions of the logical two-qubit version's black box can be queried and solved. To the best of our knowledge, this work represents the first experimental realization of the quantum algorithm solving Simon's Problem. The experimental results are in excellent agreement with the theoretical model, demonstrating the successful performance of the algorithm. With a view to scaling up to larger numbers of qubits, we analyze the resource requirements for an n-qubit version. This work helps highlight how one-way quantum computing provides a practical route to experimentally investigating the quantum-classical gap in the query complexity model.Comment: 9 pages, 5 figure

Bacteria consortia and deterioration of archaeological waterlogged wood: identification by molecular and microscopy techniques

In this study molecular tools are applied to reveal and identify bacterial colonization in waterlogged wood to assessing the changes induced in anatomical structure, previously observed by Optical and Scanning Electron Microscopy (1). The results obtained by observation of wooden thin sections (OM), shown the presence of black and dark-brown areas and mineral concretions. The SEM analysis revealed a specific cell walls alteration, attributable to bacterial activity, other than abundant pyrite framboids (FeS2). The presence of sulfur compounds in archaeological waterlogged wood can indicate both long-term burial in anoxic environment and colonization by sulfate-reducing bacteria. Molecular methods allow us extract microbial genomic DNA from wood samples and in vitro amplify (PCR) bacteria DNA target sequences (16S, ITS-rRNA) (2). Through sequences analysis of PCR products cellulosolytic and ligninolytic bacteria, such as Pseudomonas, Cellulomonas, Xanthomonas and Bacillus spp, have been revealed. Moreover the presence of Marinobacter sp. and Desulforudis audaxviator, respectively iron-oxidizing and sulfate-reducing bacteria, are identify. We hypothesize that this investigation approach, can be applied to a variety of wooden artifacts of archaeological findings for both characterization of microbial colonization in order to understanding the main degradation phenomena, indispensable for a correct conservation strategies. (1) Safa A. et al. (2012) Using SEM in monitoring changes in archaeological wood: A review. Current Microscopy Contributions to Advances in Science and Technology (A. Méndez-Vilas, Ed.) (2) Palla, F., (2012) Analytical techniques: analysis of microbial colonization. In Science and Conservation in Museum Collections, B. Fabbri (ed), Nardini, Firenze. 14, 459-470

OTTIMIZZAZIONE DI GIUNTI IBRIDI HBB A DOPPIA SOVRAPPOSIZIONE GFRP-ALLUMINIO

In order to exploit the advantages of both mechanical joints and adhesively bonded joints, in the last year a noticeable research activity has addressed to the so called hybrid joints (Hybrid Bonded Bolted joint, HBB) that consist in combining a classical mechanical joint (bolted, riveted joint, etc..) to a traditional bonded joint or a co-cured joint. The present work shows the results of experimental and numerical analyses of double-lap HBB joints, carried out to detect the geometric configuration that permits to distribute the applied load between the two coexisting junctions and then to optimize their mechanical performance. The studied joint consists of an internal adherent made by GFRP and external adherents made by aluminum type 2024-T6, connected by using an adhesive bonding and a M6 bolt. The optimization is detected by varying various influence parameters such as the geometry of the lip and the shape of the washer, which influences the distribution of the bolt preload. After the experimental tests, various numerical analyses are carried out to obtain a better understanding of the static behavior of the joint, as well as to define reliable criteria for the strength prediction under various operating conditions

DNA analysis as tool for identification of bacteria in archaeological waterlogged wood

Abstract In this work molecular techniques were applied in order to integrete the results obtained by Optical (OM) and Scanning Electron (SEM) Microscopy, to understanding and assessing the changes in the anatomical structure of archaeological waterlogged wood (Pinus sp.) induced by bacteria colonization. Observation of wooden thin sections revealed by OM showed the presence of black and dark -brown areas (must probably due to sulphur compounds) and mineral concretions. The SEM micrographs revealed a specific cell wall alteration attributable to bacterial activity and abundant pyrite framboids (as single structure or clustered). The presence of sulfur compounds in archaeological waterlogged wood, indicate both long-term burial in anoxic environment and colonization by sulfate-reducing bacteria. Molecular biology investigation was performed through ad hoc protocols by direct DNA extraction from wood samples and in vitro amplification of bacteria DNA target sequence (16S, ITS regions-r RNA). The results reveal and identify bacterial genus as Pseudomonas, Cellulomonas, Xanthomonas and Bacillus that, as reported in the related scientific literature, are the most common cellulosolytic and ligninolytic bacteria. Moreover were also revealed the presence of Marinobacter sp. and Desulforudis audaxviator, respectively iron- oxidizing and sulfate- reducing bacteria. The investigation protocol set up in this work can be applied to a range of wooden artifacts of archaeological findings for both identification of bacteria colonization shed some light on the degradation phenomena, indispensable for correct conservation and restoration strategies