Palermo città tutto porto

il testo presenta il progetto per il nuovo porto di Palermo con un'intervista al presidente dell'Autorità portuale: quest'ultima sta svolgendo rapidamente un'azione di rinnovamento sia delle strutture del porto sia degli spazi pubblici posti a margine della città

Understanding the role of the anode on the polarization losses in high-temperature polymer electrolyte membrane fuel cells using the distribution of relaxation times analysis

To investigate the role of the anode on the polarization losses of a High-Temperature Polymer Electrolyte Membrane Fuel Cell (HT-PEMFC), we analyzed impedance data using the Distribution of Relaxation Times (DRT) method. Thereby, we varied the operating conditions of the anode (humidification, nitrogen dilution, and carbon monoxide (CO) impurities) to study its impact on Nyquist plot and DRT spectrum. Humidification of the hydrogen was found to dilute phosphoric acid, which is visible in the DRT. Nitrogen dilution of the anode gas slightly increases the Mass Transport (MT) resistance. Furthermore, CO was added to anode gas fed and it impacts the impedance throughout the whole frequency range, specifically the medium and low-frequency range, typically assigned to ORR kinetics and oxygen MT. For a more detailed analysis of the impedance data, a reference electrode was employed to separate the overpotential caused by each electrode. The DRT spectrum of the anode exhibits only one peak at 1 kHz. In the presence of CO, a second peak arises corresponding to side-reactions occurring as the anodic half-cell potential increases. It was found that the cathode is affected by CO on the anode merely by the lowered cell potential and not by CO directly

Recovery of residual copper from low-content tailings derived from waste electrical cable treatment

The current work aims at the recovery of residual copper from electrical cables with low content of copper (less than 5%). The sample originated from the tailings of electrical cables that had been previously subjected to copper recycling treatment. The tailings were successively treated with physical methods (sieving, heavy medium sep- aration in ZnCl2 bath, and counter-current separation) and electrochemical methods (cementation, electrowin- ning). Sieving seems to be more efficient than gravity separation methods, since, for 1.00 mm aperture and sieving time as short as 2 min, the undersize copper grade of the product was 57% in copper (from 4% in the feed), with corresponding copper recovery of 53%. Longer sieving times or larger apertures led to products with higher copper recovery but of lower grade. As regards cementation, preliminary tests were carried out to investigate the effect of pH using high purity CuSO4 \ub7 5H2O instead of dissolving metallic copper. Subsequent tests using the sieving undersize product of the scrap copper wire confirmed the results of the preliminary tests; in addition to pH, this product was also used to investigate the effects of the attacking chemical (H2SO4, HCl, H2O2), sacrificial metal (aluminium, iron scrap), temperature, and surface area on cementation. The results show that cementation of the dissolved copper from scrap wire is efficient at pH = 2.5\u20133.2, with sufficient copper recovery within a few hours. Also, electrowinning tests on the undersize sieving product proved the feasibility to obtain pure copper by electrodeposition onto stainless steel cathode with lead anode, without contamination of the electrolytic solution. In both methods, copper purity degrades when HCl acid is used instead of H2SO4. Espe- cially with the use of H2SO4 in electrowinning, it was observed that lead anode is passivated when the solution is entirely depleted from copper ions. The results of the current work clearly demonstrate the feasibility to obtain pure copper from low-grade electric wire scraps by successively submitting the tailings to sieving and cementation

Mapping Connections between Neighborhoods in Response to Community-Based Social Needs

Geographic proximity might not be the only factor influencing the connections between neighborhoods within the same city. Most likely, the community's needs and behaviors play a role in facilitating or hindering any connections between these urban areas. Accordingly, relationships between communities may differ or be similar based on their respective characteristics. This paper aims to demonstrate that communities are close based on the needs they share, regardless of their ethnicity or geographic location. In this study, a time series analysis of neighborhoods' needs is explored to gain a deeper understanding of the communities' network. The study takes into account the co-occurrence of complaints/reports from residents regarding the same issue. The dataset was retrieved from the Boston Area Research Initiative (BARI) and the 311 system that describe the features of neighborhoods regarding non-emergency issues. Subsequently, the connection between neighborhoods in the City of Boston was analyzed using a mixture of PCA, K-means, association rule mining, and a network creation tool. Moreover, clustering coefficients and degrees of centrality were used as significant factors in identifying the members of groups and marking crucial nodes in the network. A series of graphs were generated to show how the neighborhoods are linked based on their socioeconomic concerns. The results prove that even geographically disconnected neighborhoods within Boston have similar social needs, despite their distance from one another. Furthermore, it revealed that some neighborhoods can act as linking bridges for other neighborhoods, while others may be isolated within the network graph. This study has increased awareness of urban aspects. The authorities may consider other dimensions than the traditional ones regarding neighborhood development and addressing problems. Finally, it helps to identify common characteristics between neighborhoods, which facilitates the policy making process

A new class of sum rules for products of Bessel functions

In this paper we derive a new class of sum rules for products of the Bessel functions of first kind. Using standard algebraic manipulations we extend some of the well known properties of $J_n$. Some physical applications of the results are also discussed. A comparison with the Newberger[J. Math. Phys. \textbf{23} (1982) 1278] sum rules is performed on a typical example.Comment: Published in Journal of Mathematical Physics, 9 pages, no picture

Phosphoric Acid Invasion in High Temperature PEM Fuel Cell Gas Diffusion Layers

In this work, liquid phosphoric acid was injected into polymer electrolyte membrane fuel cell (PEMFC) gas diffusion layers (GDLs) to visualize the invasion patterns developed at breakthrough. Three-dimensional (3D) images of the GDLs were obtained through X-ray computed tomography, and equivalent pore networks were generated as the basis for pore network simulations using OpenPNM. Strong qualitative agreement was obtained between the simulated and experimentally observed liquid phosphoric acid invasion patterns, which provided validation for the numerical modeling. Different GDL materials were evaluated by examining the effects of a micro porous layer (MPL) and pore size distribution on the saturation and distribution of phosphoric acid. The MPL was shown to restrict liquid phosphoric acid from entering the carbon fiber substrate. The overall phosphoric acid saturation at breakthrough was found to decrease significantly for samples containing an MPL due to the smaller pore sizes. Further, the influence of cracks in an MPL on overall saturation at breakthrough was investigated. It was observed that a crack-free MPL provided a more effective physical barrier to restrict the undesired leaching of liquid phosphoric acid through the GDL

A complete parton level analysis of boson-boson scattering and ElectroWeak Symmetry Breaking in lv + four jets production at the LHC

A complete parton level analysis of lv + four jets production at the LHC is presented, including all processes at order O(alpha^6), O(alpha^4*alpha_s^2) and O(alpha^2*alpha_s^4). The infinite Higgs mass scenario, which is considered as a benchmark for strong scattering theories and is the limiting case for composite Higgs models, is confronted with the Standard Model light Higgs predictions in order to determine whether a composite Higgs signal can be detected as an excess of events in boson--boson scattering.Comment: More detailed discussion of the effects of the reconstruction of the longitudinal neutrino momentum. Improved figures. To be published in JHE

Effects of ultrasound treatments on wine microorganisms

Ultrasound is one of the most promising non-thermal an emerging technique in food technology. The objective of the present work was to evaluate the effect of different ultrasonic treatments on the most important wine microbiota (Saccharomyces and non-Saccharomyces yeasts and lactic acid bacteria). Two stages were carried out: the assessment step, where six different ultrasonic treatments (with varying power, time, and pulses) were used on Saccharomyces cerevisiae, Brettanomyces spp., and Lactiplantibacillus plantarum; and the validation step, where two chosen ultrasonic treatments were used on Zigosaccharomyces bailli, Brettanomyces spp., Saccharomyces cerevisiae, Saccharomyces bayanus, Pichia membranifaciens, Schizosaccharomyces pombe, and Hanseniaspora osmophila. The most sensitive microorganism was Brettanomyces spp., and the most resistant was Lactiplantibacillus plantarum. Ultrasonic treatments had varying effects on vitality (delay of growth or maximum OD reduction) and on viability (reduction of microbial growth)

How well can the LHC distinguish between the SM light Higgs scenario, a composite Higgs and the Higgsless case using VV scattering channels?

A complete parton level analysis of ll + four jets l = e,mu and 3lv + two jets production at the LHC is presented, including all processes at order \ordEW, \ordQCD and \ordQCDsq when appropriate. The infinite Higgs mass scenario, which is considered as a benchmark for strong scattering theories and is the limiting case for composite Higgs models, and one example of a model incorporating a Strongly Interacting Light Higgs are confronted with the Standard Model light Higgs predictions. This analysis is combined with the results in the lv + four jets channel presented in a previous paper, in order to determine whether a composite Higgs signal can be detected as an excess of events in boson--boson scattering.Comment: Introduced some representative Feynman diagrams. Rearranged section 4. Typos fixed. Published in JHE