161 research outputs found
Generalised bisection method for optimum ultrasonic ray tracing and focusing in multi-layered structures
No full textUltrasonic testing has been used for many decades, proving itself very efficient for detecting defects in many industrial sectors. The desire to apply ultrasonic testing to geometrically complex structures, and to anisotropic, inhomogeneous materials, together with the advent of more powerful electronics and software, is constantly pushing the applicability of ultrasonic waves to their limits. General ray tracing models, suitable for calculating the proper incident angle of single element probes and the proper time delay of phased array, are currently required. They can support the development of new imaging techniques, as Full Matrix Capture and Total Focusing Method, and the execution of very challenging ultrasonic inspections. This paper introduces a generalized iterative method for the computation of ultrasonic ray paths, when ultrasonic source and target are separated by multiple complex material interfaces in the two dimensional and three dimensional domains. The manuscript starts with a review of the well-known bisection method, and extends the applicability of the method to cases with increasing complexity. An application example, in the field of in-process weld inspection, shows that the introduced generalised bisection method can enable the computation of optimum incidence angles and focal delays for accurate ultrasonic focusing. There is no restriction on the analytical interfaces to be surjective. Interface folding is permitted. It is not necessary to know, a priori, with what sequence the interfaces are crossed by the rays. The presented implementation of the method completes each iteration of the bisection method in 4 ms, for a case with a single interface, and in 960 ms for the case with 52 interfaces
CarMineo/autonomousRoboticSensing: autonomousRoboticSensing - v1.0
No full textThe main script (MAIN.m) and all associated functions, demonstrate the work related to the paper titled: "Autonomous Robotic Sensing for Simultaneous Geometric and Volumetric Inspection of Free-Form Parts", by C. Mineo, D. Cerniglia and A. Poole
CarMineo/fineImageAlignmentMethod-FiPAM: FiPAM v1.0
No full textThis is the first release of the Fine Pixel-based Alignment Method (FiPAM). In order to demonstrate FiPAM, the present script is provided with the dataset of thermographic images presented in the journal paper, titled: "Fine Alignment of Thermographic Images for Robotic Inspection of Parts with Complex Geometries", by C. Mineo, N. Montinaro, M. Fustaino, A. Pantano and D. Cerniglia. This script executes FiPAM and plots the results
Fine Alignment of Thermographic Images for Robotic Inspection of Parts with Complex Geometries
No full textIncreasing the efficiency of the quality control phase in industrial production lines through automation is a rapidly growing trend. In non-destructive testing, active thermography techniques are known for their suitability to allow rapid non-contact and full-field inspections. The robotic manipulation of the thermographic instrumentation enables the possibility of performing inspections of large components with complex geometries by collecting multiple thermographic images from optimal positions. The robotisation of the thermographic inspection is highly desirable to improve assessment speed and repeatability without compromising inspection accuracy. Although integrating a robotic setup for thermographic data capture is not challenging, the application of robotic thermography has not grown significantly to date due to the absence of a suitable approach for merging multiple thermographic images into a single presentation. Indeed, such an approach must guarantee accurate alignment and consistent pixel blending, which is crucial to facilitate defect detection and sizing. In this work, an innovative inspection platform was conceptualised and implemented, consisting of a pulsed thermography setup, a six-axis robotic manipulator and an algorithm for image alignment, correction and blending. The performance of the inspection platform is tested on a convex-shaped specimen with artificial defects, which highlights the potential of the new combined approach. This work bridges a technology gap, making thermographic inspections more deployable in industrial environments. The proposed fine image alignment approach can find applicability beyond thermographic non-destructive testing
Su alcune specie di Telenomus Haliday nuove per l\u27Italia e descrizione di due nuovi generi di Telenomini e tre nuove specie di Telenomus
No full textThe paper deals mostly with Palaearctic Telenomini material collected all over Sicily by the author. Among this material there are some species new to Island or to Italy (Telenomus acrobates Giard., T. angustatus Thomson, T. antennalis Kozlov, T. danubialis (Szelenyi), T. dissolcus Kozl., T. lopicida Silvestri, T. macroceps Szabò, T. regius Kononova, T. tauricus Konon., as well as the new genera Rachelia n. gen., (type species Rachelia robertae n. sp.), and Televiggianus n. gen., (type species Televiggianus rachelinae n. sp.). Furthermore, a new species from Zimbabwe, Telenomus rachelae Mineo, is described; Telenomus paraothus Szabò & Mineo has also been re-defined; Telenomus sp., bred from Liorhyssus hyalinus F. (Rhopalidae), is recognized as a new parasitoid of this bug in the Palaearctic region.Sono stati studiati dei materiali di Telenomini (Scelionidae) raccolti per lo più in alcune località della Sicilia. Tra essi sono stati identificati alcune specie già note, sebbene quasi tutte nuove per l\u27Italia, cioe: Telenomus acrobates Giard., T. angustatus Thomson, T. antennalis Kozlov, T. danubialis (Szelenyi), T. dissolcus Kozl., T. lopicida Silvestri, T. macroceps Szabo, T. regius Kononova, T. tauricus Konon.; inoltre vengono proposti i seguenti due nuovi generi di Telenomini: Rachelia gen. n. e Televiggianus gen. n., i cui genotipi sono rispettivamente, Rachelia robertae sp. n. e Televiggianus rachelinae sp. n.; inoltre viene ridescritto Telenomus paraothus Szabò & Mineo. Viene descritta una nuova specie raccolta nel Zimbabwe: Telenomus rachelae Mineo e viene segnalata una specie di Telenomus nuovo parassitoide del Rhopalidae Liorhyssus hyalinus F. nella regione paleartica
Studio numerico e sperimentale sulla generazione degli ultrasuoni tramite sorgente laser puntiforme
No full textAn experimental and numerical study on the ultrasonic fields generated in metals by a point laser source has been done. Energy and profile of the beam, pulse duration, extent and shape of the irradiated area affect amplitude, frequency and directionality of the ultrasonic waves. The study has been developed for the thermoelastic regime, where the laser radiation with low energy density limits the amplitude of ultrasounds and therefore the sensitivity in detecting the defects in extended bodies. By controlling some parameters the signal-to-noise ratio can be increased. The experimental study has been conducted by varying the impact area, the distribution of the beam energy in the impact area and the receiving direction. The numerical analysis replicates the experimental acquisitions, extending the analysis to measurements that can not be handled in the laboratory. The results of this work may provide a guide for choosing the optimal configuration
The Political Logic of Conflict. A Debate on Machiavelli in Tumult by Gabriele Pedullà. Introduction
No full textThis section of the issue offers a debate on G. Pedullà’s Machiavelli in Tumult: The Discourses on Livy and the Origins of Political Conflictualism (Cambridge 2018). Its ambition is to bring together textual and philological analysis that is «internal» to the great fabric of Machiavellian exegesis, alongside
theoretical-political questioning «external» to that fabric. The main objective is to offer a new image of Machiavelli as an author who breaks with a long and authoritative tradition, one which exalted concord as an absolute political value, and to inaugurate a new way of observing political and social phenomena. The book is discussed by A. Brown, J. Hankins, J. Mc-Cormick, and N. Urbinat
Il discours préfaciel della prima edizione del Dictionaire italien, latin et françois (1735) di Annibale Antonini
No full textThe preface to Annibale Antonini’s first edition of Dictionaire italien, latin et françois (1735)
This article aims at analysing Annibale Antonini’s preface to the first edition of Dictionaire italien, latin et françois (1735) according to the topics identified by Francœur (2001) and Emanuele (2018). We will demonstrate how Antonini’s preface represents a remarkable paratextual element in which the author expresses his point of view in relation to the previous French-Italian lexicography and to the organization of the microstructure and macrostructure. We will also draw attention to Antonini’s considerations about the Italian language. In doing so, we will provide documentary evidence of the author’s contribution to the French-Italian literary polemic, known as the Orsi-Bouhours controversy. The last part of our study will be dedicated to Antonini’s unaccomplished project of writing a Universal Italian Dictionary, in order to evaluate the impact of Enlightenment on the lexicographer’s latest work
Solving ultrasonic ray tracing in parts with multiple material layers through root-finding methods
No full textUltrasonic testing has been used for material analysis and inspection since 1930's. Nevertheless, the applicability of ultrasonic waves to new complex cases is still growing, thanks to the availability of powerful electronics and software. However, the complication that slows down the deployment of ultrasonic inspection to geometric complex parts and structures arises from the wave refraction phenomenon. A clear understanding of the ultrasound wave propagation, impacted by refractions, is crucial to interpret the data obtained from the inspection of multi-layered/multi-medium test subjects as it is not always possible to assume that mechanical waves travel in straight lines. This work presents suitable approaches for solving the ray-tracing problem in multi-layered structures. Accurate benchmarking shows that the use of the Newton-Raphson root-finding method allows a threefold reduction of the computation time, when compared to the bisection-based root-finding methods. An effective combination of the Newton-Raphson methods with bisection-type iterations is also proposed and discussed. Although the work repeatedly refers to the field of ultrasonic inspection, the presented findings are relevant and applicable to areas beyond material inspection
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