Leak Detection in a Branched System by Inverse Transient Analysis with the Admittance Matrix Method

The diagnosis of water distribution systems by means of the inverse transient analysis requires efficient and reliable numerical models. In the network admittance matrix method (NAMM) the 1-D waterhammer governing equations are integrated in the frequency domain and organized in a laplacian matrix form. The NAMM is particularly suitable for complex systems because of this structure and can be used for the system diagnosis, including leak sizing and location. In this paper a damaged branched system is considered and the diagnosis is performed by means of the NAMM using experimental data from laboratory transient tests. Two different boundary conditions are used in the implementation of the NAMM and the leak is located and sized with a reasonable approximation. An extended numerical investigation is also presented and allows confirmation of the results for different leak locations. The use of the NAMM for the leak detection and the validation using experimental data on a branched system are the main original contributions of this work. The successful diagnosis indicates promising results for applications in more complex systems.     

The Photophysics of Polythiophene Nanoparticles for Biological Applications

In this work the photophysics of poly(3-hexylthiophene) nanoparticles (NPs) is investigated in the context of their biological applications. The NPs, made as colloidal suspensions in aqueous buffers, present a distinct absorption band in the low-energy region. On the basis of systematic analysis of absorption and transient absorption (TA) spectra taken under different pH conditions, this band is associated with charge-transfer states generated by the polarization of loosely bound polymer chains and originating from complexes formed with electron-withdrawing species. Importantly, the ground-state depletion of these states upon photoexcitation is active even on microsecond timescales, thus suggesting that they act as precursor states for long-living polarons; this could be beneficial for cellular stimulation. Preliminary transient absorption microscopy results for NPs internalized within the cells reveal the presence of long-living species, further substantiating their relevance in biointerfaces.     

Carbon xerogels as electrodes for supercapacitors. The influence of the catalyst concentration on the microstructure and on the electrochemical properties

Carbon xerogels, synthesized through the resorcinol–formaldehyde polycondensation and subsequently dried under subcritical condition, have been studied as electrodes for supercapacitors. In particular, the influence of the catalyst concentration has been investigated by systematically changing the amount of catalyst (Na₂CO₃) utilized to synthesize the xerogels. To clarify the effect of such variable, both the surface properties and the electrochemical behavior of xerogel-based supercapacitors have been examined. From the xerogels characterization, it can be inferred that the amount of catalyst used has a strong influence on the properties of the material. Contrary to what happens with carbon aerogels, the best properties are obtained with the xerogels synthesized with the least amount of catalyst: in this case the highest measured specific capacitance of the supercapacitor cells, which is assembled coupling two symmetric electrodes in series, is 25 F/g, value that corresponds to a single-electrode specific capacitance of 100 F/g. The maximum energy storage capacity in an aqueous electrolyte is 3.1 Wh/kg. Using more concentrated catalyst solutions, the gel microstructure becomes finer, composed of smaller particles and pores, which in turns leads to an increase of the capillary drying stresses and to the collapse of the organic structure. Consequently, the shrinkage of the gels is high and the final carbon xerogels do not posses sufficient surface area and porosity to store a significative amount of energy.     

Proximity to chipboard industries increases the risk of respiratory and irritation symptoms in children: The Viadana study

Emissions related to wood production processes are a recognized health hazard for professionally exposed subjects. The health effects of living close to wood industries are not known, particularly in the pediatric population. We aimed at investigating if living close to chipboard industries is a health hazard for the children in the Viadana district (Northern Italy).In December 2006, all the children (3-14 years) living in the Viadana district, where two big chipboard industries are located, were surveyed through a parental questionnaire (n = 3854). The children were geocoded, and the distance of their houses/schools from the closest wood plant was computed.Independently of sex, age, nationality, residential area, traffic, parents' education, passive/parental smoking, questionnaire compiler and his/her environmental concern, the children living at < 2 km from chipboard industries had a greater prevalence of respiratory (OR = 1.33, 95%CI: 1.11, 1.60), cough/phlegm (OR = 1.43, 95%CI: 1.08, 1.88), nose/throat/mouth (OR = 1.47, 95%CI: 1.23, 1.75), eye (OR = 1.24, 95%CI: 1.04, 1.48) symptoms, school-days lost (OR = 1.24, 95%CI: 1.04, 1.48), and emergency (OR = 2.14, 95%CI: 1.47, 3.11) and hospital (OR = 2.21, 95%CI: 1.17, 4.18) admissions. There was an inverse dose-response relationship between the adverse health outcomes considered and the distance from the plants. The attributable fractions for the children living close to the chipboard industries were substantial, ranging from 13% (eye symptoms) to 27% (cough/phlegm).The present findings suggest that emissions from chipboard industries might have a serious impact on children's health status and should therefore be reduced and closely monitored.     

Phase evolution and thermophysical properties of plasma sprayed thick zirconia coatings after annealing

Yttria partially stabilized zirconia (YSZ) thick thermal barrier coatings were fabricated by Atmospheric Plasma Spraying (APS) and isothermally annealed at 1315 °C for different durations. The phase composition of as-sprayed and heat-treated free-standing coatings was investigated by X-ray Diffraction (XRD) and the Rietveld method was employed for quantitative phase analysis. High-temperature exposure of YSZ coatings produced the partial decomposition of metastable t′ zirconia phase and the corresponding increase in the amount of stable tetragonal t, cubic c and monoclinic m phases with increasing the aging time.     

Densified aligned carbon nanotube films via vapor phase infiltration of carbon

We report a simple way to produce fully densified aligned carbon nanotube (ACNT) films. The simultaneous growth of nanotubes and densification of the ACNT films by carbon infiltration in the interstitial spaces between nanotubes are accomplished in a single step by the combination of the chemical vapor deposition and chemical vapor infiltration processes. Scanning electron microscope analysis and microbalance measurements showed that after infiltration, the diameters of nanotubes and bulk density of the ACNT films are increased by an order of magnitude (and hence the porosity of the ACNT films is decreased). Transmission electron microscope and Raman scattering analysis showed that after densification, the nanotubes are conformally coated by partially graphitized pyrolytic carbon. The compressive modulus of the densified ACNT films could be increased by three orders of magnitude compared to the pristine ACNT films. Electrical properties are also measured for the densified films showing marked differences with the ACNT films. The property enhanced densified ACNT films constitute a new form of carbon-carbon nanocomposites and could find applications as multifunctional nanocomposites.     

Integrating services and tools in an ICT platform to support eco-innovation in SMEs

Small and medium-sized enterprises (SMEs) represent a key vector to introduce and diffuse eco-innovation in the market, because of their relevance to both the environment and the European gross domestic product. As they are often focused on continuous and incremental innovation of their products, the optimization of product eco-innovation paths can be considered a central aspect of their business. All phases of this process (awareness building and training, analysis, product (re)design and communication/certification) need to be supported to overcome the existing barriers, which mainly consist of lack of experience inside SMEs and cost of information, data, and tools. Information and Communication Technologies can play a role to lower some of the barriers, but currently the numerous services and tools available cover only specific aspects of the whole process, and are often too complex for their direct use by SMEs. The multilingual web-based platform Ecosmes.net here presented aims to integrate user-friendly and free-of-charge services and tools to support all phases of the product eco-innovation process in SMEs. The approach behind mainly consists in developing tailored, simplified tools, and in carrying out ??homogeneous product group?? studies, as a basis for the production of pre-elaborated information and data to be used with the tools developed. Experience gained in 5?years of applications has confirmed that Ecosmes.net can facilitate the start-up of the product eco-innovation process, but has also shown that not all the potentialities have been fully exploited. Moreover, as the eco-innovation market is not developed enough to allow economic management of these kinds of online services, a public initiative is advocated to face this challenge and support a continuous upgrading. Modes and opportunities are proposed and discussed in the conclusion.     

Enhanced utilisation of nonmarketable fish: physical,nutritional and sensory properties of ‘clean label’ fish burgers

Four ‘clean label’ formulations for fish burgers made with mechanically separated fish meat were characterised in sensory, textural and chemical terms. The formulations differed in the ratios of European sea bass to rainbow trout (50:50 and 30:70) and the ratios of fish to potato flakes (dry matter ratio, DMR: 2.5:1 and 1.5:1). The sensory profile was mainly influenced by DMR. Recipes with the higher DMR were positively correlated with sandy, dry and crusty attributes, salty taste and overall flavour. Soft texture was perceived for recipes with the lower DMR, although no differences in texture were detected by a texturometer. Lowering DMR increased ash and water content and decreased protein content, as expected. The results indicated that 100 g of burger provided more essential fatty acids than the recommended daily intake, irrespective of formulation. In conclusion, multiple factor analysis indicated that the main changes detected and perceived were due to DMR.