Search results for "Amination"

Stable carbon and nitrogen ratios (δ13Corg and δ15Ntot) of core sediments from the Gulf of Palermo (NW Sicily): implications for the carbon source

2010

ASSESSMENT OF HEAVY METAL CONTAMINATION IN TERRACES FOR PUBLIC USE RECOVERED IN THE CITY OF PALERMO AND IN AGRICULTURAL TERRACES

2017

The contamination by heavy metals in the soil is nowadays considered an indicator of environmental pollution caused by to several factors, such as waste disposal, industrial discharges and the use of irrigation water. Developed in collaboration with SO.GEST Ambiente Laboratory, in Palermo, this study had as a purpose to monitor the levels of heavy metals - Cd, Cr, Fe, Mn, Pb, Zn -both in public lands and in agricultural terrains. All the soil samples collected have been subjected to an acid extraction process by using HCL and eventually to a mass spectrometer-based analysis for the quantitative/ qualitative determination, specifically by the technique of flame atomic absorption spectrophoto…

ARCHITETTURE PER LE ACQUE SOTTERRANEE. CONSERVAZIONE E VALORIZZAZIONE DEL PATRIMONIO CAVO A PALERMO

2019

The valorisation policies and protection of “visible” architectural heritage are often promoted by the public opinion, that immediately perceives in the artefacts degradation the risk of an irreparable loss. Conversely, the safeguard of the underground built heritage is ever more difficult to achieve. It is the case of the "hollow architecture" functional to ensuring water provisioning in the Piana di Palermo: “horizontal wells” and “qanat”. These artefacts date back to the sixteenth century, though an older dating is not to be excluded. The need for studies on underground historical construction is more evident if we consider the scarcity of documentary material and specialised literature.…

Cyclic Delamination Analysis: Experimental and Cohesive-Frictional interface Finite Element Modelling

2011

ELEMENTO D’INTERFACCIA PER LA SIMULAZIONE DI PROCESSI DI DANNEGGIAMENTO IN MODO MISTO I/II NEI MATERIALI COMPOSITI E NELLE GIUNZIONI ADESIVE

2018

E’ stato sviluppato un elemento coesivo in grado di connettere e simulare la crescita delle cricche tra sottodomini di elementi finiti modellati in modo indipendente con mesh incompatibili. L'approccio si basa su funzioni di penalità e presenta numerosi vantaggi rispetto alle tecniche FEM convenzionali nelle simulazioni di delaminazione. Il più importante è la possibilità di rilasciare una porzione dell'interfaccia più piccola della lunghezza degli elementi finiti locali. Pertanto la delaminazione non avanza solamente rilasciando i nodi del modello FEM, una limitazione comune a molti metodi trovati in letteratura. È stato anche sviluppato un nuovo approccio per modellare la crescita delle c…

A penalty-based interface technology

2009

Modern computers have enabled engineers to perform large scale analyses of complex structures like entire aircrafts, automobiles, and ships. One issue that arises often is the need to perform a unified analysis of a structural assembly using sub-structural models created independently. These sub-structural models are frequently designed by different engineers, thus they are likely to be incompatible at their interfaces. Finite element interface technology has been developed to facilitate the joining of independently modeled substructures. Here an effective and robust interface element is presented. This method has been developed using penalty constraints and allows computationally efficient…

The effect of the through-the-thickness compressive stress on mode II interlaminar fracture toughness

2017

The effect of through-the-thickness compressive stress on the mode II interlaminar fracture toughness is investigated experimentally and replicated numerically. The modified Transverse Crack Tensile specimen recently proposed by the authors is used, together with an experimental device designed to apply a constant transverse compressive stress on the surface of the specimen. Experiments are conducted using IM7/8552 specimens for different compressive stresses, ranging from 0 to 100 MPa, covering all the practical applications commonly encountered in the aeronautical industry (e.g., tightened filled holes or bolted joints). It is shown that the mode II interlaminar fracture toughness increas…

Mode I fracture toughness behaviour of epoxy resincarbon fiber composites cured by ionising radiation

2012

In this work Mode I fracture toughness behavior of Electron Beam cured unidirectional CFRP laminates is investigated by means of standardized Double Cantilever Beam (DCB) tests. A matrix system, comprising a DGEBA epoxy monomer and a typical initiator of cationic polymerization, was used and panel samples assembled by hand lay-up. Curing was achieved by 20 to 40 minutes irradiation on a pulsed 10 MeV Electron Beam accelerator. One batch of resin was also mixed with 10 phr of a PES thermoplastic monomer in order to enhance the matrix toughness. The influence of fibre-matrix adhesion, matrix toughening and matrix crosslinking density on the mode I delamination behavior have been investigated …

Experimental evaluation of through-the-thickness stress distribution in transverse crack tension test samples

2015

Transverse Crack Tension (TCT) samples represent an alternative to End Notched Flexure configurations for the characterization of pure mode II fracture toughness of Fibre Reinforced Polymer composites. TCT is supposed to reproduce a pure Mode II failure mechanism while avoiding the frictional energy dissipation between the flanks of a starter crack. The TCT geometry is that of a unidirectional tensile sample where a number of embedded plies, centered on the middle plane, are cut in the transverse fibres direction. The tensile loading should then activate four symmetric fronts of mode II delamination from the transverse cut tips. The present work describes the implementation of two full fiel…

A Novel Ionic Exchange Membrane Crystallizer to Recover Magnesium Hydroxide from Seawater and Industrial Brines

2020

A novel technology, the ion exchange membrane crystallizer (CrIEM), that combines reactive and membrane crystallization, was investigated in order to recover high purity magnesium hydroxide from multi-component artificial and natural solutions. In particular, in a CrIEM reactor, the presence of an anion exchange membrane (AEM), which separates two-compartment containing a saline solution and an alkaline solution, allows the passage of hydroxyl ions from the alkaline to the saline solution compartment, where crystallization of magnesium hydroxide occurs, yet avoiding a direct mixing between the solutions feeding the reactor. This enables the use of low-cost reactants (e.g., Ca(OH)2) without …