Industrial Engineering

The aim of this study was the surface functionalization of a new green ceramic material, obtained using packaging glass waste (PGW), to improve its cleanability. This objective was reached through the deposition by air-brushing of a nanostructured coating based on titania–silica sol–gel suspension. The coatings were deposited on both glazed and unglazed ceramic substrates and the thermal treatment conditions (temperature) were optimized. The obtained results suggest that the applied coatings are transparent and show a good scratch resistance and photocatalitic activity under the tested conditions. The photodegradation process and the mechanical properties are clearly affected by the thermal treatment and thus by the sample surface roughness. The best surface properties were obtained with a thermal treatment at temperature of 150 1C. These coatings do not exhibit either cracks from the substrate. All in all, the developed surface modified ceramic material is attractive as potential sustainable building material.

A series of diblock copolymers of n-pentyl methacrylate and methyl methacrylate (PPMA/PMMA BCP) with one or two terminal functional groups was prepared by sequential anionic polymerization of PMA and MMA using an allyl-functionalized initiator and/or and end-capping with allyl bromide. Allyl functional groups were successfully converted into OH groups by hydroboration. The morphology in bulk was examined by temperature-dependent small-angle X-ray measurements (T-SAXS) and transmission electron microscopy (TEM) showing that functional groups induced a weak change in d-spacings L 0 as well as in the thermal expansion behavior. T-SAXS proved that the lamellar morphologies were stable over multiple heating/cooling cycles without order-disorder transition (ODT) until 300 C. While non-functionalized BCP formed parallel lamellae morphologies, additional OH-termination at the PMMA block forced in very thin films (ratio between film thickness and lamellar d-spacing below 1) the generation of perpendicular lamellae morphology through the whole film thickness, as shown by Grazing-incidence small-angle X-ray scattering experiments (GISAXS) measurements. Functionalized BCP were successfully used in thin films as templates for silica nanoparticles in an insitu sol-gel process. V C 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 926-937, 2011

CNT were dispersed in an epoxy matrix and cured by means of UV light. An increase on elastic modulus and T g values was measured by DMTA analysis and attributed to the constraint effect of CNT on polymer chain mobility. Excellent scratch resistant coatings characterized by high critical load, small cracks and high recovery were obtained in the presence of a very low CNT content (0.025 wt.-%). TEM analysis showed some isolated CNT and some cluster agglomerations of size of about 250 nm. It was shown that it was possible to decrease the surface resistivity of the cured samples by three orders of magnitude in the presence of 0.1 wt.-% of SWCNT content.

BACKGROUND: The reinforcement of elastomers by the addition of fillers is one of the most important aspects in rubber science and technology. In order to optimise the filler-polymer interface, innovative in situ generation of silica within isoprene rubber was carried out by means of a bottom-up approach through a sol-gel process starting from tetraethoxysilane as silica precursor. The main aim was the study of the effect of the silica concentration and of the presence of coupling agent on the morphology and the dynamic mechanical behaviour of the composites.

In this study, we reported the studies on a glass-ceramic foam with wollastonite and cristobalite micrometric crystals prepared by sintering a borosilicate glass waste with organic binder as foaming agent. The waste glass, coming from the dismantling of washing machine, was characterized by high CaO content and low-temperature sinterability. The effect of the temperature on the sinter-crystallization ability of the borosilicate glass waste was followed with thermal analysis, heating microscopy, and electron scanning microscopy (ESEM) observations. Additionally, the effect of temperature on the evolution of crystalline phases and density variation was monitored with XRD and density measurements. The softening started at 800°C and crystallization at 845°C to be completed at 900°C with a linear expansion of 38-40% in the range 850-900°C. Wollastonite and cristobalite were identified as crystalline phases in variable proportions dependently upon temperature. No crack evidence was found at high ESEM magnification even though cristobalite crystals were present. The final products showed a total porosity around 78-79% and an apparent density of about 0.5 g/cm 3 , in line with common porous closed-cell glass foams used for thermal insulation.

Lightweight geopolymers from wastes with reduced thermal conductivity have become an important
trend for green buildings sector. In this work, organic-inorganic hybrid geopolymers were prepared from
polyurethane powders wastes (polyurethane foam and polyisocianurate foam). Chemical, physical and
mechanical properties of geopolymers, manufactured with different percentages of polyurethane wastes
are reported and discussed. The FTIR spectroscopy allowed to verify the influence of both polyurethane
powders on the framework structure revealing H-bonds between polyurethane and inorganic phase.
Flexural and compressive strengths showed that content and typology of the used polyurethane wastes
affected the material behavior. The strength of hybrid geopolymers was maximized with polyisocianurate
foam waste addition in a concentration lower than 14% in weight. Thermal conductivity was carried
out on appropriate samples, showing that the hybrid geopolymers exhibit satisfactory isolation properties.
The new materials proposed in this work represents an innovative solution, enhancing the thermal
resistance of the buildings by using a waste intended for landfill.

A B S T R A C T Chitosan is a biomaterial characterized by biodegradability, biocompatibility with human tissues, antimicrobial and antifungal activities, and for these reasons has been proposed in many different fields. The present work highlights the potentiality of chitosan as additive for active PVC-based composites, prepared by termo-mechanical process, with good mechanical-physical properties and antimicrobial activity. A specific mechanical characterization shows as elastic modulus and tensile strength increase with the chitosan concentration, as well as dynamical storage and loss moduli. These findings evidence that a significant interaction between chitosan and PVC occurs. The thermal stability and preliminary antimicrobial tests are encouraging.

Techniques based on impulsive sources are used since the beginning of the Underwater Acoustic science, to evaluate the distance of objects and to plot the profile of the sea bottom. In this paper the authors investigate the behavior of three not-impulsive techniques for the measurement of impulse responses: MLS (Maximum Length Sequence) signal, linear sine sweep and logarithmic sine sweep. This work will focus the attention on advantages and defects of these tree different methods, in comparison with the traditional pulse-based sonar techniques. The mathematical theory for the generation of the MLS, sine sweep signals and for the deconvolution of the system's impulse response are first described. Then a software implementation of the measurement methods, based on the creation of plug-ins for a shareware waveform editor, running on a low cost PC is demonstrated. Some experiments conducted under controlled conditions and in the sea show that the proposed techniques produce images of the bottom profile with higher signal-to-noise ratio and better spatial resolution than those obtainable with the impulsive technique. Moreover signal-to-noise ratio increases using sine sweep signal instead of MLS one. The new techniques seem superior also for some practical aspects connected with their very nature, which make them almost inaudible and makes the sound source barely localizable: this is very important for military applications.

one of the reasons to use a non-uniform linear array (NULA) is to reduce the cost and complexity of the array, since it can have fewer sensors than an ULA system. In this paper, authors describe the construction of a low-cost, ten-hydrophones, nonuniform linear array to be employed in passive and active sonar applications. Many experiments were conducted, under controlled conditions (large pool), oriented to characterize both individual transducers as well as the complete array. Using the array in "passive" mode, employing an omnidirectional sound source and a non-impulsive signal, beamforming and inverse filtering techniques, the authors evaluated array directivity over a wide range of frequencies (1-23 kHz) and also its capability to estimate the direction of arrival (DOA). Furthermore, this work also focuses on searching objects and identification. Different test were performed, in order to estimate system performances when used as the receiver of an active sonar. Using sine-sweep signals, and a specific real-time software developed by the authors, several measures were conducted in the shallow and very shallow water showing the ability of the system to detect objects in a 45° wide angle.

L'incremento della direttività del sistema è sicuramente il vantaggio più importante tra quelli derivanti dall'impiego di array di trasduttori. Normalmente, infatti, gli array sono progettati con lo scopo di massimizzare l'energia trasmessa o ricevuta da un particolare angolo, minimizzando contemporaneamente quella trasmessa o ricevuta dalle altre direzioni. Questa tecnica è conosciuta come "array beamforming".