Search results for "laser"
showing 10 items of 3161 documents
2D size, position and shape definition of defects by B-scan image analysis
2015
The non-destructive evaluation of defects by automatic procedures is of great importance for structural components. Thanks to the developments of the non-contact ultrasonic techniques, the automation of the inspections is gaining a progressively important role. In this work, an automatic inspection technique for the evaluation of defects by the analysis of B-scan images obtained by a laser ultrasonic system is presented. The data are extracted directly from a B-scan map obtained for a panel with internal defects, and are used to build an image of the cross section of the panel. The proposed automatic procedure allows the definition of size, position and shape of defects in panels of known t…
La digitalizzazione del patrimonio come strumento per la conoscenza, un’esperienza sull’architettura ferroviaria siciliana
2022
The process of digitisation of the artistic and cultural heritage has enriched the possibilities of representation and communication of architecture, increasing the modes of reproduction, fruition as well as the possibilities of protection and preservation. The study of this research draws attention on the continuous progress of technology in the cultural field and highlights the important collaboration that exists between digital and analog representation, identifying, with this synergy, a virtuous path that allows, through the use of different methodologies, to be able to know and analyze the historical phases of a building. In particular, the attention was directed to the Caltanissetta C…
La Cappella Palatina di Palermo: Misura, Interpretazione, Rappresentazione
2012
Lo studio che segue è incentrato sull'analisi delle vicende costruttive della Cappella Palatina nel Palazzo Reale di Palermo, costruita per volontà di Ruggero II nella prima metà del XII secolo. La peculiarità della Cappella è quella di aver mantenuto pressoché inalterato i caratteri spaziali dell’interno attraverso i secoli; tale peculiarità ha fatto si che la Cappella sia stata oggetto di studi molto approfonditi condotti da storici dell’arte a partire dalla del XIX secolo fino ai nostri giorni. Lo studio intende porsi come contributo alla conoscenza della Cappella, alla interpretazione di alcune questioni rimaste irrisolte, come stimolo ausiliare per successivi studi, attraverso gli stru…
GEOMATIC TECHNIQUES FOR THE COLONNADE STRUCTURAL ANALYSIS OF THE HISTORICAL “ CHIARAMONTE STERI” BUILDING
2019
The monitoring of building structures has an increasingly important role in the engineering field, above all because they are concerned with the impact that such structures have in the area where they were built. Often, when walking through the old town centres, we realize just how obsolete and dangerous some buildings (even historic-cultural ones) are. The interest of some local governments in this problem has led, in the last few years, to the study and the trying out of measuring and monitoring methods which, quickly and at low cost, allow to define the extent of the deformation and the degrade in an accurate and reliable way. The Courtyard of “Palazzo Steri - Chiaramonte” is composed of…
TECNOLOGIE DI RILIEVO 3D PER LA DOCUMENTAZIONE, L’INTERPRETAZIONE E LA VALORIZZAZIONE DEL PATRIMONIO ARCHEOLOGICO: IL CASO STUDIO DEL PARCO ARCHEOLOG…
2020
In recent decades, the application of geomatics technologies and methodologies to archaeological studies has led to a substantial change in onsite survey techniques and allowed an interdisciplinary approach between archaeology and digital technologies. The employment of these techniques aims to reduce the time of research and documentation, to acquire large amounts of data and to manage, in a more efficiently and quickly way, different datasets. Moreover, these new approaches provide non-invasive, flexible, low-cost methodologies to improve archaeological documentation from a quantitative and qualitative point of view. Nowadays, archaeologists can take advantage of various recording techniq…
Porous 3D Printed Scavenger Filters for Selective Recovery of Precious Metals from Electronic Waste
2018
Selective laser sintering (SLS) 3D printing is used to fabricate highly macroporous ion scavenger filters for recovery of Pd and Pt from electronic waste. The scavengers are printed by using a mixture of polypropylene with 10 wt% of type‐1 anion exchange resin. Porosities and the flow‐through properties of the filters are controlled by adjusting the SLS printing parameters. The cylinder‐shaped filters are used in selective recovery of Pd and Pt from acidic leachate of electronic waste simply by passing the solution through the object. Under such conditions, the scavenger filters are able to capture Pd and Pt as anionic complexes with high efficiency from a solution containing mixture of dif…
3D Printed Palladium Catalyst for Suzuki-Miyaura Cross-coupling Reactions
2020
Selective laser sintering (SLS) 3d printing was utilized to manufacture a solid catalyst for Suzuki-Miyaura cross-coupling reactions from polypropylene as a base material and palladium nanoparticles on silica (SilicaCat Pd(0)R815-100 by SiliCycle) as the catalytically active additive. The 3d printed catalyst showed similar activity to that of the pristine powdery commercial catalyst, but with improved practical recoverability and reduced leaching of palladium into solution. Recycling of the printed catalyst led to increase of the induction period of the reactions, attributed to the pseudo-homogeneous catalysis. The reaction is initiated by oxidative addition of aryl iodide to palladium nano…
Design, characterization, and first field deployment of a novel aircraft-based aerosol mass spectrometer combining the laser ablation and flash vapor…
2021
In this paper, we present the design, development, and characteristics of the novel aerosol mass spectrometer ERICA (ERC Instrument for Chemical composition of Aerosols; ERC – European Research Council) and selected results from the first airborne field deployment. The instrument combines two well-established methods of real-time in situ measurements of fine particle chemical composition. The first method is the laser desorption and ionization technique, or laser ablation technique, for single-particle mass spectrometry (here with a frequency-quadrupled Nd:YAG laser at λ = 266 nm). The second method is a combination of thermal particle desorption, also called flash vaporization, and electro…
Caracterización de protones acelerados por láser y estudio de aplicaciones médicas
2017
El desarrollo de técnicas de amplificación láser durante las últimas décadas [1] ha derivado en una tecnología capaz de generar pulsos ultracortos, decenas de femtosegundo, y ultraintensos, en el orden del terawatio-petawatio. Estos pulsos pueden ser utilizados como vehículo para la aceleración de partículas hasta energías multi-MeV [2]. Esto ha generado un gran interés de la comunidad científica por la posibilidad de utilizar esta tecnología, que podría tener virtudes frente a los mecanismos de aceleración convencionales, además de ser un terreno inexplorado. El objetivo principal es el diseño de un experimento, detectores de partículas, y todos los periféricos necesarios para demostrar la…
Calibration of the photon spectrometer PHOS of the ALICE experiment
2019
Journal of Instrumentation 14(05), P05025 - P05025 (2019). doi:10.1088/1748-0221/14/05/P05025