Image Based Modeling Technique for Pavement Distress surveys: a Specific Application to Rutting

Image-based modeling (IBM) is a well-known technique to obtain high quality 3D models based on multi view images. IBM started being used in several applications such as inspection, identification of objects and visualization, due to the user-friendly approach, the low cost and highly automated technique. This paper focuses on the investigation of the potential application of IBM in the diagnosis of road pavement distresses and in particular rutting. Indeed, the evaluation of the rutting distress is a fundamental step to define the whole state of a pavement as demonstrated by the calculation of Present Serviceability Index (PSI). Currently, the permanent deformation is measured monitoring visually the rut depth with the approximations that this procedure involves. Nevertheless, the exact measure of the rut depth is necessary to evaluate precisely the cause and the severity of this distress and be effective in the maintenance and rehabilitation of the pavement structure. The objective of this study is to apply the IBM technique on a laboratory rutted sample, in order to verify the accuracy of the method in determining the rut depth. To achieve this, a comparison has been made between the 3D model obtained with IBM and the one obtained with blue led 3D scan (Artec Spider) of the same rutted asphalt concrete. The metric accuracy of the model is then defined and its validity is assessed, in terms of distress diagnosis

Synthesis, studies and fuel cell performance of “core–shell” electrocatalysts for oxygen reduction reaction based on a PtNix carbon nitride “shell” and a pyrolyzed polyketone nanoball “core”

This report describes a new class of "core-shell" electrocatalysts for oxygen reduction reaction (ORR) processes for application in Proton Exchange Membrane Fuel Cells (PEMFCs). The electrocatalysts are obtained by supporting a "shell" consisting of PtNix alloy nanoparticles embedded into a carbon nitride matrix (indicated as PtNix-CN) on a "core" of pyrolyzed polyketone nanoballs, labeled 'STp'. ST(p)s are obtained by the sulfonation and pyrolysis of a precursor consisting of XC-72R carbon nanoparticles wrapped by polyketone (PK) fibers. The ST(p)s are extensively characterized in terms of the chemical composition, thermal stability, degree of graphitization and morphology. The "core-shell" ORR electrocatalysts are prepared by the pyrolysis of precursors obtained impregnating the STp "cores" with a zeolitic inorganic-organic polymer electrolyte (Z-IOPE) plastic material. The electrochemical performance of the electrocatalysts in the ORR is tested "in situ" by single fuel cell tests. The interplay between the chemical composition, the degree of graphitization of both PtNix-CN "shell" and STpS "cores", the morphology of the electrocatalysts and the fuel cell performance is elucidated. The most crucial preparation parameters for the optimization of the various features affecting the fuel cell performance of this promising class of ORR electrocatalysts are identified

Evaluation of electrospun spinel-type high-entropy (Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)3O4, (Cr0.2Mn0.2Fe0.2Co0.2Zn0.2)3O4 and (Cr0.2Mn0.2Fe0.2Ni0.2Zn0.2)3O4 oxide nanofibers as electrocatalysts for oxygen evolution in alkaline medium

Electrochemical water splitting is a promising sustainable-energy technology, but the slow kinetics of the oxygen evolution reaction represents a limitation for its broad market penetration. Spinel-structured transition metal (TM) oxides have shown great potential as a sustainable alternative to precious metal-based electrocatalysts. High-entropy oxides (HEOs) with multiple TM-cation sites lend themselves to engineering of the octahedral redox-active centres to enhance the catalyst reactivity. This work focuses on the preparation of electrospun spinel-type HEO nanofibers (NFs), based on equimolar (Cr,Mn,Fe,Co,Ni), (Cr,Mn,Fe,Co,Zn) and (Cr,Mn,Fe,Ni,Zn) combinations, and their evaluation as electrocatalysts in alkaline medium together with (Cr,Mn,Fe,Co,Ni) HEO nanoparticles (NPs) prepared via the sol-gel method. (Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)3O4 NFs and NPs (Tafel slopes: 49.1 and 51.3 mV dec−1, respectively) outperform both (Cr0.2Mn0.2Fe0.2Co0.2Zn0.2)3O4 and (Cr0.2Mn0.2Fe0.2Ni0.2Zn0.2)3O4 NFs (62.5 and 59.6 mV dec−1, respectively) and IrO2 reference electrocatalyst (52.9 mV dec−1). The higher concentration of oxygen vacancies on their surface and the higher occupation of octahedral sites by redox-active Co2+ and Ni2+ centres are responsible for their behaviour. The present electrospun HEO NFs have great potential as ink-jet printable electrocatalysts

Esophageal atresia in newborns: a wide spectrum from the isolated forms to a full VACTERL phenotype?

Background: VATER association was first described in 1972 by Quan and Smith as an acronym which identifies a non-random co-occurrence of Vertebral anomalies, Anal atresia, Tracheoesophageal fistula and/or Esophageal atresia, Radial dysplasia. It is even possible to find out Cardiovascular, Renal and Limb anomalies and the acronym VACTERL was adopted, also, embodying Vascular, as single umbilical artery, and external genitalia anomalies. Methods: Data on patients with esophageal atresia (EA) with or without tracheoesophageal fistula (TEF) admitted in the Neonatal Intensive Care Unit (NICU) between January 2003 and January 2013 were evaluated for the contingent occurrence of typical VACTERL anomalies (VACTERL-type) and non tipical VACTERL anomalies (non-VACTERL-type). The inclusion criterion was the presence of EA with or without TEF plus two or more of the following additional malformations: vertebral defects, anal atresia, cardiovascular defects, renal anomalies and lower limb deformities, like radial dysplasia. Results: Among 52 patients with EA/TEF, 20 (38,4%) had isolated EA and 7 (21,8%) had a recognized etiology such a syndrome and therefore were excluded. Among 32 infants with EA and associated malformations, 15 (46,8%) had VACTERL association. The most common anomalies were congenital heart defects (73,3%), followed by vertebral anomalies (66,6%). Many patients also had additional non-VACTERL-type defects. Single umbilical artery was the most common one followed by nervous system abnormalities and anomalies of toes. Between the groups of infants with VACTERL type and non-VACTERL-type anomalies, there are several overlapping data regarding both the tipically described spectrum and the most frequently reported non-VACTERL-type malformations. Thus, it is possible to differentiate infants with a full phenotype (VACTERL full phenotype) and patients that do not meet all the criteria mentioned above, but with some homologies with the first group (VACTERL partial phenotype). Conclusion: The high frequency of non-VACTERL-type anomalies encountered in full and partial phenotype patients would suggest the need for an extension of the clinical criteria for the diagnosis of VACTERL association and also for pre- and post-operative management and follow-up in the short and long term

Assessment of contamination of Salmonella spp. in imported black pepper and sesame seed and salmonella inactivation by gamma irradiation

This study shows the frequency of seeds samples contaminated by Salmonella spp. collected randomly from local markets; on 30 black pepper sample no contaminated sample was found while Salmonella spp. was detected in 3 of 36 (8.3%) analyzed sesame samples; three different serotypes were identified: S. Montevideo, S. Stanleyville e S. Tilene. The efficacy of gamma irradiation to inactivate Salmonella Montevideo in black pepper and sesame irradiated between 1 and 5 kGy was evaluated. 3 kGy is sufficient to reduce of 3-4 log CFU/g; whereas 5 kGy have been need to reduce 5.5-6 log CFU/g for samples of black pepper and sesame. No statistically significant differences were found between black pepper and sesame

Positronium cooling at cryogenic temperature for advanced experiments

New Ps spectroscopy measurements, formation of antihydrogen for antimatter-matter comparison experiments, production of Ps beams require the efficient production of cooled positronium in vacuum. At present the most efficient positron-positronium converters are silica based ordered or disordered porous materials, in which formed Ps decreases its kinetic energy by collisional cooling. Recently new positron-positronium converters based on oxidized nanochannels in silicon were found to be very promising because of the tunability of the nanochannel size, which allows to overcome the limits imposed to the Ps cooling by the quantum confinement. With these converters, Ps with temperatures as low as 150 K was detected in vacuum by a TOF apparatus. The Ps formation, quantum confinement, collisional cooling and emission into vacuum from nanochanneled silicon will be discussed in light of recent results

Successful control of an outbreak of colonization by Klebsiella pneumoniae carbapenemase-producing K.\ua0pneumoniae sequence type 258 in a neonatal intensive care unit, Italy

This article reports an outbreak of colonization by Klebsiella pneumoniae carbapenemase-producing K. pneumoniae (KPC-Kp) sequence type (ST) 258 in a neonatal intensive care unit (NICU) in Palermo, Italy. KPC-Kp ST258 was detected by an active surveillance culture programme. Between 18th September and 14th November 2012, KPC-Kp was isolated from 10 out of 54 neonates admitted in the outbreak period. No cases of infection were recorded. Male sex was associated with colonization, whereas administration of ampicilline-sulbactam plus gentamicin was protective. Infection control interventions interrupted the spread of KPC-Kp without the need to close the NICU to new admissions. (C) 2013 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved

Structure and magnetism of electrospun porous high-entropy (Cr1/5Mn1/5Fe1/5Co1/5Ni1/5)3O4, (Cr1/5Mn1/5Fe1/5Co1/5Zn1/5)3O4 and (Cr1/5Mn1/5Fe1/5Ni1/5Zn1/5)3O4 spinel oxide nanofibers

High-entropy oxide nanofibers, based on equimolar (Cr,Mn,Fe,Co,Ni), (Cr,Mn,Fe,Co,Zn) and (Cr,Mn,Fe,Ni,Zn) combinations, were prepared by electrospinning followed by calcination. The obtained hollow nanofibers exhibited a porous structure consisting of interconnected nearly strain-free (Cr1/5Mn1/5Fe1/5Co1/5Ni1/5)3O4, (Cr1/5Mn1/5Fe1/5Co1/5Zn1/5)3O4 and (Cr1/5Mn1/5Fe1/5Ni1/5Zn1/5)3O4 single crystals with a pure Fd3̄m spinel structure. Oxidation state of the cations at the nanofiber surface was assessed by X-ray photoelectron spectroscopy and cation distributions were proposed satisfying electroneutrality and optimizing octahedral stabilization. The magnetic data are consistent with a distribution of cations that satisfies the energetic preferences for octahedral vs. tetrahedral sites and is random only within the octahedral and tetrahedral sublattices. The nanofibers are ferrimagnets with relatively low critical temperature more similar to cubic chromites and manganites than to ferrites. Replacing the magnetic cations Co or Ni with non-magnetic Zn lowers the critical temperature from 374 K (Cr,Mn,Fe,Co,Ni) to 233 and 105 K for (Cr,Mn,Fe,Ni,Zn) and (Cr,Mn,Fe,Co,Zn), respectively. The latter nanofibers additionally have a low temperature transition to a reentrant spin-glass-like state