1Department of Information Engineering, Electronics and Telecommunications, Sapienza University of Rome, Via Eudossiana 18, 00184 Rome, Italy 2Physics Department and STAR infrastructure, University of Calabria, I-87036 Arcavacata di Rende, CS, Italy 3Department of Information Engineering, University of Brescia, Via Branze 38, 25123 Brescia, Italy 4Université de Limoges, XLIM, UMR CNRS 7252, 123 Avenue A. Thomas, 87060 Limoges, France 5Institute of Automation and Electrometry, SB RAS, Novosibirsk 630090, Russia 6Novosibirsk State University, Pirogova 1, Novosibirsk 630090, Russia †These authors have contributed equally *Corresponding author: mario.ferraro@uniroma1.it

Multiphoton ionization of standard optical fibers

: In spite of their ubiquitous applications, the characterization of glass ﬁbers by means of all-optical techniques is still facing some limitations. Recently, X-ray absorption has been proposed as a method for visualizing the inner structure of both standard and microstructure optical ﬁbers. Here, we exploit X-ray absorption as nondestructive technique for the characterization of optical glass ﬁbers. Starting from absorption contrast X-ray computed micro-tomography measurements, we obtain information about the spatial proﬁle of the ﬁber refractive index at optical frequencies. We conﬁrm the validity of our approach by comparing its results with complementary characterization techniques, based on electron spectroscopy or multiphoton microscopy. Publishing Group under the terms of the Optica Publishing Group Publishing Agreement

X-ray computed $\mu$-tomography for the characterization of optical fibers

3D printing is a widespread technology in different fields, such as medicine, construction, ergonomics, and the transportation industry. Its diffusion is related to the ability of this technique to produce complex parts without needing for assembly of different components or post-processing. However, the quality of the parts produced by additive manufacturing could be affected by the fabrication process, thus leading to the development of different kinds of defects such as porosity or inclusions. Understanding the role played by these defects and promoting strategies that could help reduce their occurrence represents a key point to allow using 3D printing for structural applications. In this work, 3D printed parts have been subjected to porosity characterization by using experimental tests on dogbone samples subjected to plastic deformation. In particular, multiple loading-unloading steps have been carried out and, at the end of each step, the X-ray computed micro-tomography (μ-CT) has been employed for the identification of fabrication defects and for analyzing the crack growth mechanism that occurs after quasi-static loading tests. Sample analysis reveals the presence of a high porosity that could be attributed to the fabrication process. After the sample’s plastic deformation, it was found an increase in both porosity percentage and pore dimensions. Moreover, the crack propagation mechanism is affected by porosity. 

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Effect of induced plastic strain on the porosity of PA12 printed through selective laser sintering studied by X-ray computed micro-tomography

/pdf/evidence-for-stages-of-landscape-evolution-in-central-mexico-197lzcs2.pdf

Evidence for stages of landscape evolution in Central Mexico during the late Quaternary from paleosol-pedosediment sequences

Abstract 3D printing is a widespread technology in different fields, such as medicine, construction, ergonomics, and the transportation industry. Its diffusion is related to the ability of this technique to produce complex parts without needing for assembly of different components or post-processing. However, the quality of the parts produced by additive manufacturing could be affected by the fabrication process, thus leading to the development of different kinds of defects such as porosity or inclusions. Understanding the role played by these defects and promoting strategies that could help reduce their occurrence represents a key point to allow using 3D printing for structural applications. In this work, 3D printed parts have been subjected to porosity characterization by using experimental tests on Dogbones samples subjected to plastic deformation. In particular, X-ray computed micro-tomography (μ-CT) has been employed as an investigation tool for the identification of fabrication defects and for analyzing the crack growth mechanism that occurs after subjecting samples to quasi-static loading conditions. 

This work presents the results of the study of a fragment of architectural terracruda sculpture from the Buddhist archaeological site of Tepe Narenj (Kabul, Afghanistan, fifth-ninth centuries CE) t...

Architectural Terracruda Sculptures of the Silk Roads: New Conservation Insights Through a Diagnostic Approach Based on Non-Destructive X-ray Micro-Computed Tomography

Sudipa Ray Bandyopadhyay

Papers

Architectural Terracruda Sculptures of the Silk Roads: New Conservation Insights Through a Diagnostic Approach Based on Non-Destructive X-ray Micro-Computed Tomography