1,721,009 research outputs found
Flexible CMUT as smart tool for nondestructive testing of aircraft composite structures
No full textIn avionics, safety is a crucial aspect and nondestructive testing (NDT) is a mandatory inspecting procedure to ensure the quality of materials before and during the lifetime of the aircraft, evaluating both the status of the materials and the degradation of the different parts of an aircraft. Especially in recent composites like Carbon Fibre Reinforce Plastics the presence of defects or the disbonds caused from accidental impacts can be very dangerous for the integrity of the wings, fuselage, etc. Among the different methods implemented in non-destructive testing, ultrasonic testing is the most common sub-surface technique to detect defects in welds, fittings, joints, bolts and adhesive bond quality. Capacitive Micromachined Ultrasonic Transducers (CMUTs) can be utilized to this end, thus permitting portable and potentially low-cost inspection. In this work, we present the fabrication and characterization of flexible CMUTs, and we discuss their potential use in NDT probes to be embedded directly on the aircraft to allow continuous and real-time monitoring of the different parts of an aircraft
Demonstration of PolyimideBased Flexible CMUT Operation on Curved Substrates
No full textCapacitive micromachined ultrasonic transducers (CMUTs) represent a class of ultrasonic devices widely investigated for several applications such as medical imaging and non-destructive material inspections. Although many improvements, the possibility to successfully operate on nonplanar surfaces still remains challenging. In this respect, flexible electronics can represent a unique ally to enable the manufacturing ultra-thin highly conformable CMUTs. In this paper, we demonstrate a fully flexible fabrication process for a PI based CMUT device and a preliminary characterization. This flexible CMUT technology was conceived to achieve a final device composed of only two materials, i.e., Titanium for the electrodes and PI for the membrane and the backplate. The CMUT cavities were realized by Aluminium sacrificial release. We fabricated flexible CMUT test devices consisting of 7 membranes 50μm in diameter laying onto an 8μm-thick backplate. This configuration can allow the bending of the devices on very small curvature radii (down to 1 mm)
Dielectric Characterization of Structural and Passivation Films for Flexible CMUT Microfabrication
No full textPolymer-based CMUT microfabrication approaches allow low-cost fabrication of flexible transducers. However, they are characterized by processing limitations mainly related to the low glass transition temperature of polymers, reducing the possible choice of materials that can be used for electrodes and in-cavity passivation layers, the latter having a major impact on transducer performance and reliability. In this paper, we experimentally evaluate the electrical properties of these two materials in terms of dielectric dispersion and losses, and high electric field response with respect to state-of-the-art materials
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Al cospetto di Dante. La politicità di Petrarca nel Novecento
No full textIl saggio affronta il tema della politicità di Petrarca a partire dal confronto con Dante, durante la prima metà del XX secolo. Viene dunque esaminato un capitolo di storia del pensiero politico e di storia intellettuale italiana, per verificare se, e in quali forme, l’accostamento fra i due grandi classici abbia contribuito al divenire di una riflessione critica sul Petrarca politico, valorizzando quelle culture che hanno ricalibrato il rapporto fra i due autori, nel segno della modernità di Petrarca. In un contesto scandito dalla tradizione del neoidealismo italiano e dalla storiografia del pensiero politico primo novecentesca, un singolare interesse rivestono i saggi di Giovanni Gentile e Rodolfo De Mattei, che leggono in Petrarca il dissolvitore della Scolastica e il moderno pioniere di una filosofia dell’uomo, ma anche il promotore di una dimensione spirituale e non naturalistica della politica
An Infrared Sensor Tx/Rx Electronic Card for Aerospace Applications
No full textAn electronic sensor card for aerospace applications is presented. The device uses infrared technology to transmit measurements toward a central unit. It has been designed following a low power consumption strategy which allows the use of a mini photovoltaic panel supplier. The card could be efficiently used in structures which ensure the line of sight between the card and a central receiver unit as inflatable structures. The device has been realized and tested
La beatitudine "huius vite"
No full textLa beatitudine huius vite è il tema attorno al quale ruota lʼintera speculazione filosofica di Dante. Contrariamente a quanti sostengono lʼesistenza nellʼuomo di un solo fine ultimo, la beatitudine eterna, in funzione della quale egli ordina lʼintera sua vita e predispone ogni altro suo fine, Dante afferma lʼesistenza anche di un fine naturale, la felicità terrena, alla quale riconosce piena dignità e completa autonomia. Una felicità che lʼuomo potrà conseguire per «phylosophica documenta», per mezzo cioè degli insegnamenti filosofici, ed è la sola a cui egli può realisticamente aspirare in vita. Condizione necessaria perché l'uomo raggiunga la piena capacità intellettiva è la pace la quale potrà essere garantita dall’istituzione di una Monarchia universale in cui lʼimperatore è il solo, attraverso la sua azione, in grado di tenere a freno ogni desiderio di conquista. Due fini, terreno e ultraterreno, per i quali sono concepiti due poteri, temporale e spirituale, ciascuno sovrano e indipendente nel proprio ambito, poiché entrambi trovano origine direttamente da Dio, che è il creatore dell'universo
Dante e il cattolicesimo politico in epoca risorgimentale
No full textIl saggio ricostruisce le principali interpretazioni politiche dell’opera dantesca promosse, nel corso del Risorgimento, all’interno dell’ampio ed eterogeneo schieramento cattolico, che vedeva contrapposti i fautori di un cattolicesimo d’ispirazione liberale e filorisorgimentale e coloro che, invece, si opponevano alle ideologie e ai modelli della società moderna trincerandosi a difesa delle prerogative del clero e del potere temporale della Chiesa. Nella prima metà dell’Ottocento, entrambe le compagini, nonostante le loro inconciliabili posizioni politiche, colsero elementi di convergenza nei giudizi su Dante, ritenuto rispettoso dei dogmi del cattolicesimo e dell’autorità pontificia, a cui non perdonarono, però, «la strana aberrazione» della Monarchia, rimasta all’Indice fino al 1900. Con il conseguimento dell’indipendenza nazionale i contrasti tra i due partiti del cattolicesimo politico italiano si fecero però insanabili e coinvolsero anche il pensiero e gli scritti del Fiorentino, reputato dai paladini del nuovo Regno d’Italia preconizzatore dell’unità nazionale, di una monarchia temperata di libertà e del disfacimento del potere temporale dei papi.The essay reconstructs the main political interpretations of Dante’s work promoted, during the Risorgimento, within the wide and heterogeneous catholic party. It saw opposed the advocates of Catholicism of a liberal inspiration and those who, on the contrary, were counterposed to the ideologies and models of the modern society. In the first half of the Nineteenth Century, both parties, despite their irreconcilable political positions, understood points of agreement in their judgements concerning Dante, who was considered respectful towards the dogmas of Catholicism and the Pontifical authority. Nevertheless, he was not forgiven «the strange aberration» of Monarchia introduced into the Index until 1900. Subsequently the achievement of national independence the hinders between the two political parties turned out to be irreconcilable, affecting doubtless the thought regarding the Florentine writer, who was considered by the champions of the Kingdom of Italy, the forerunner of national unity, of a tempered monarchy and the decay of the temporal power held by the popes
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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