2011

Organic-inorganic materials to be used as hydrophobic consolidants for plasters were synthesized starting from an inorganic precursor (Tetraethoxysilane [TEOS]), added to a polysiloxane epoxy formulation and thermally cured with Ytterbium as acid catalyst. The TEOS reduces the viscosity of the resin, contributing to the mechanical properties of the film, without causing cracking. Solvents, that are harmful for workers and environment and show some drawbacks in the practice of restoration, were not used. The film properties and the formation of silica clusters were investigated.

Dense and cellular yttria-tetragonal zirconia polycrystal (Y-TZP) bodies were produced by using a natural gelatine and two different agars as gelling agents, while commercial polyethylene (PE) spheres were added (125 to 300 μm diameter) as a volatile pore forming agent to create 50-65 vol% spherical macro-pores, uniformly distributed in a micro-porous matrix. The microstructure of all dense and cellular ceramics was characterized by FEG-SEM and Focused Ion Beam (FIB) techniques.

Alkaline (lithium, potassium, rubidium) and alkaline-earth (magnesium, barium) doped hematite materials were studied for NO2 sensing application. The synthesized materials were characterized by laser granulometry, X-ray diffraction and scanning electronic microscopy. A temperature of 1300 °C was chosen as the optimal heat treatment in order to obtain the densest material.

The present paper reviews the current state of the art of carbon nanotubes cement-based composites and the possible applications. The influence of carbon nanotubes additions onto cement paste mechanical and electrical properties are discussed in detail. Though promising, several challenges have still to be solved before the introduction of these new materials into the public sphere through civil infrastructures.

Analysis of the grain growth on the galvanic deposition of aluminium is presented aiming to find an optimized process and corresponding ad-hoc designed experimental set-up which guarantees an enhanced quality of the coated layer. In particular, the effects of some process parameters, i.e. deposition time, current density and the liquid agitation on the coating properties of aluminium have been experimentally investigated.The properties of the deposited layer has been evaluated.

One of the most favored welding techniques of high strength aluminium alloy is commonly metal arc welding (MAW) process due to its high productivity and relatively low production cost. Apart from other process parameters (e.g. joint design) the filler material has a significant influence on the microstructure of the weld at the joint and consequently on the endurance limit of the end-product. The above considered process was used to weld AA6082 aluminum alloy using two different filler metals, Al4043 and Al5356 respectively.

In this paper dimensional stability investigation in two hypoeutectic composition is proposed. Specifically, the study of some samples in AlSi7Mg0,3 and AlSi8,5Cu3,5 alloys is realized and a comparison of the obtained data will be discussed. Starting from dilatometric analysis the dimensional modification of the alloys is monitored. For both materials analysis has been conducted by heating to 500°C at various heating rates and determining the activation energy for the decomposition process of the supersaturated solid solution.

Assessment of facial soft tissues could be implemented using only anatomical landmarks. These points are so significant in the medical context because are able to provide significant information about the human face morphology and dimensions. At present their detection and location is made by expert physicians using palpation. Even if this procedure normally provides reliable information, the reliability of the results is proportional to the expertise of the physician.

Well-dispersed nano-crystalline transition alumina suspensions were mixed with yttrium chloride aqueous solutions, with the aim of producing Al2O3–Y3Al5O12 (YAG) composite powders. DTA analysis allowed to highlight the role of yttrium on the α-phase crystallization path. Systematic XRD and HRTEM analyses were carried out in parallel on powders calcined in a wide temperature range (600–1300 °C) in order to follow phase and microstructural evolution.