Modelling guided waves in anisotropic plates using the Legendre polynomial method

A numerical method to compute phase dispersion curve in unidirectional laminate is described. The basic feature of the proposed method is the expansion of fields quantities in single layer on different polynomial bases. The Legendre polynomial method avoid to solve the transcendental dispersion equation of guided wave. Guided waves that have very close propagation constants are calculated with great accuracy. Numerical solution of dispersion relation are calculated for guided waves propagation in orthotropic unidirectional fiber composites. The validation of the polynomial approach is depicted by a comparison between the associated solution and those obtained using Transfer matrix method

New anti-perovskite-type Superconductor ZnNyNi3

We have synthesized a new superconductor ZnNyNi3 with Tc ~3 K. The crystal structure has the same anti-perovskite-type such as MgCNi3 and CdCNi3. As far as we know, this is the third superconducting material in Ni-based anti-perovskite series. For this material, superconducting parameters, lower-critical field Hc1(0), upper-critical field Hc2(0), coherence length x(0), penetration depth l(0), and Gintzburg -Landau parameter k(0) have been experimentally determined.Comment: 13 pages, 3 figures, 1 tabl

Enhanced performance of polybenzimidazole-based high temperature proton exchange membrane fuel cell with gas diffusion electrodes prepared by automatic catalyst spraying under irradiation technique

Gas diffusion electrodes (GDEs) prepared by a novel automatic catalyst spraying under irradiation (ACSUI) technique are investigated for improving the performance of phosphoric acid (PA)-doped polybenzimidazole (PBI) high temperature proton exchange membrane fuel cell (PEMFC). The physical properties of the GDEs are characterized by pore size distribution and scanning electron microscopy (SEM). The electrochemical properties of the membrane electrode assembly (MEA) with the GDEs are evaluated and analyzed by polarization curve, cyclic voltammetry (CV) and electrochemistry impedance spectroscopy (EIS). Effects of PTFE binder content, PA impregnation and heat treatment on the GDEs are investigated to determine the optimum performance of the single cell. At ambient pressure and 160 o C, the maximum power density can reach 0.61 W cm-2, and the current density at 0.6 V is up to 0.38 A cm-2, with H /air and a platinum loading of 0.5 mg cm-2 on both electrodes. The MEA with the GDEs shows good stability for fuel cell operating in a short term durability test.Web of Scienc

Nanocomposite SPEEK-based membranes for Direct Methanol Fuel Cells at intermediate temperatures

Novel nanocomposite membranes were prepared by infiltration of a blend of sulfonated PEEK (SPEEK) with polyvinyl alcohol (PVA), using water as solvent, into electrospun nanolibers of SPEEK blended with polyvinyl butyral (PVB). The membranes were characterized for their application on Direct Methanol Fuel Cells (DMFCs) operating at moderate temperatures (>80 degrees C). An important role of the solvent on the crosslinking temperature for the SPEEK-PVA system was observed. A mat of hydrated SPEEK-30%PVB nanofibers revealed higher proton conductivity in comparison with a dense membrane of similar composition. Incorporation of the nanoliber mats to the SPEEK-35%PVA matrix provided mechanical stability, methanol barrier properties and certain proton conductivity up to a crosslinking temperature of 120 degrees C. Not remarkable effect of the nanofibers was found above that crosslinking temperature. The combined effect of the nanofibers and crosslinking temperature on the properties of the membranes is discussed. DIV1FC performance experiments concluded promising results for this new low-cost type of membranes, although further optimization steps are still required.This research has been funded by the R&D Support Programmes of the Polytechnic University of Valencia (project 24761) and the Spanish Ministry of Science and Innovation (project SP-ENE-20120718).Mollá Romano, S.; Compañ Moreno, V. (2015). Nanocomposite SPEEK-based membranes for Direct Methanol Fuel Cells at intermediate temperatures. Journal of Membrane Science. 492:123-136. https://doi.org/10.1016/j.memsci.2015.05.055S12313649

A microporous six-fold interpenetrated hydrogen-bonded organic framework for highly selective separation of C 2

A unique six-fold interpenetrated hydrogen-bonded organic framework (HOF) has been developed, for the first time, for highly selective separation of C2H4/C2H6 at room temperature and normal pressure

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised