1,721,388 research outputs found
Energy release as a parameter for fatigue design of additive manufactured metals
Full text linkAdditive manufacturing (AM) is spreading in a wide range of industrial fields. The influence of the printing parameters on the mechanical performance is still an open issue among researchers, particularly when dealing with fatigue loads, which can lead to an unexpected failure. Classical fatigue tests require a large amount of time and materials to be consumed. Compared to the traditional fatigue assessment, the thermographic method (TM) is able to derive in a very rapid way the SN curve and fatigue limit of the material monitoring its energetic release during fatigue tests. In this work, for the first time, the energetic release during fatigue test has been evaluated in specimens made of AISI 316L, obtained by SLM technique. Compared to literature data, the specimens show premature failure, even at low stress levels, with brittle fracture surfaces. The internal microstructure seems to be strictly related to the energetic release of the material
Elogio del testo (e dell’autore): il caso del ‘Conde Lucanor’ di Juan Manuel
No full textUn buon numero degli studi dedicati al Conde Lucanor nell’ultimo ventennio hanno insistito sull’ambiguità, la problematicità, le aporie rintracciabili nel suo sistema di significazione, che renderebbero necessaria, anche nella sua prima parte, un’attiva cooperazione interpretativa del destinatario, cui sarebbe demandata la responsabilità ultima della ‘produzione del senso’. Questa duttilità ermeneutica si rivelerebbe ancor più eclatante dal confronto tra i differenti “stati” assunti dal testo nel corso della sua diffusione: la micro e macro variance esibita da un testimone rispetto all’altro e l’inserimento in contesti librari diversi comproverebbero che esso si prestava, o meglio invitava, a letture plurime, variamente orientate. Tuttavia un testo non è mai materia inerte che si offre ad ogni possibile deriva dei suoi significati, ma in esso è presente «una quiddità a cui le nostre affermazioni devono necessariamente far riferimento» (Cesare Segre), se intendiamo realmente tentare di approfondirne la comprensione. Ciò vale a maggior ragione per un testo dichiaratamente didattico, scarsamente reticente e a forte impronta autoriale come il Conde Lucanor; è noto che, in special modo nella prima sezione del Libro, don Juan Manuel pone in essere un complesso dispositivo di mediazioni e di implicazioni chiamato ad assolvere un triplice ufficio: interpretativo, generalizzante e pragmatico. È a partire da queste considerazioni che, esaminando tre casi ‘esemplari’ (es. 1, es. 39, alcune particolarità del manoscritto P), si proverà qui a riesaminare la questione, la quale comporta, come è chiaro, implicazioni metodologiche non secondarie.A good number of studies devoted to Conde Lucanor last twenty years have insisted on the ambiguity, the problematic, the aporias traceable in his system of signification, that would make necessary, even in its first part, an active interpretive cooperation of the recipient, which ultimate responsibility for the ‘production of meaning’ would be left. This ductility hermeneutics would prove even more striking by the comparison between the different ‘states’ hired by the text in the course of its spread: the micro and macro variance exhibited by a witness over the other and the inclusion in different contexts library would prove that it lent, or rather invited, to multiple readings, variously oriented. However a text is never inert matter that is offered to every possible dreft of its meanings, but in it there is «una quiddità a cui le nostre affermazioni devono necessariamente far riferimento» (Cesare Segre), if we are really groped to deepen understanding. This applies even more so for an avowedly educational text, slightly secretive and whit a strong authorial imprint as the Conde Lucanor; it is known that, especially in the first section of the book, Don Juan Manuel introduces a complex device of mediations and implications required to perform a threefold mission: interpreting, generalizing and pragmatic. It is from these considerations that, by examining three cases ‘exemplary’ (enxiemplo 1, enxiemplo 39, some peculiarities of the manuscript P), the report will try to review the issue, which involves, as is clear, methodological implications not secondary.Un buen número de los estudios dedicados al Conde Lucanor en los últimos veinte años han insistido en la ambigüedad, la problematicidad, las aporías localizables en su sistema de significación, que harían necesaria, incluso en su primera parte, una activa cooperación interpretativa del destinatario, al cual se le exigiría la responsabilidad última de la ‘producción del sentido’. Esta ductilidad hermeneútica se revelaría de forma aún más evidente por la comparación entre los varios ‘estados’ asumidos por el texto en el curso de su difusión: la micro y macro variance exhibida por un testigo respecto al otro y la introducción en contextos libreros distintos darían la prueba de que él se prestaba, o mejor dicho invitaba, a lecturas múltiples, orientadas variadamente. Sin embargo un texto no es nunca materia inerte que se entrega a cualquier posible deriva de su significado, pero en este está presente «una quiddità a cui le nostre affermazioni devono necessariamente far riferimento» (Cesare Segre), si pretendemos realmente intentar profundizar en su comprensión. Esto vale con mayor razón para un texto declaradamente didáctico, escasamente reticente y con una fuerte huella autorial como el Conde Lucanor; es sabido que, de manera particular en la primera sección del Libro, don Juan Manuel pone en marcha un complejo dispositivo de mediaciones y de implicaciones llamado a desempeñar un tríplice oficio: interpretativo, generalizador y pragmático. Es a partir de estas consideraciones que, examinando tres casos ‘ejemplares’ (ej. 1, ej. 39, algunas particularidades del manuscrito P), se intentarà volver a examinar la cuestión, la cual conlleva, claro está, implicaciones metodológicas no secundarias
Determination of fatigue limit by static thermographic method and classic thermographic method on notched specimens
Full text linkThe aim of the present work is to investigate the possibility to evaluate the fatigue limit of such a component through the so-called Static Thermographic Method (STM). This new approach has been proposed in 2013 by Risitano and Risitano to determinate the fatigue limit of metallic materials through static tensile tests. Investigating the trend of the surface temperature of the material during static tensile test, the method proposes to correlate the first deviation from linearity of the surface temperature to a damage limit that has been proven to have relation with the fatigue limit. Static tensile tests at different stress rate have been carried out on V-notched specimens. Stepwise fatigue tests have been carried out in order to apply the classic Thermographic Method that has been hugely validated to determinate the fatigue limit of metallic components. Static tests at different stress rate showed that the method is dependent on this parameter; anyway, this dependence does not affect the results achieved in terms of fatigue limit. The experimental results showed a good agreement with the energetic methods considered in the present work
Smart Design of Hip Replacement Prostheses Using Additive Manufacturing and Machine Learning Techniques
No full textThe field of additive manufacturing, particularly 3D printing, has ushered in a significant transformation in the realm of joint arthritis treatment through prosthetic surgery. This innovative technology allows for the creation of bespoke prosthetic devices that are tailored to meet the specific needs of individual patients. These devices are constructed using high-performance materials, including titanium and cobalt-chrome alloys. Nevertheless, the routine physical activities of patients, such as walking, sitting, and running, can induce wear and tear on the materials comprising these prosthetic devices, subsequently diminishing their functionality and durability. In response to this challenge, this research has endeavored to leverage novel techniques. The primary focus of this study lies in the development of an algorithm designed to optimize hip replacement procedures via the mechanical design of the prosthesis. This optimization process exploits the capabilities of machine learning algorithms, multi-body dynamics, and finite element method (FEM) simulations. The paramount innovation in this methodology is the capacity to design a prosthetic system that intricately adapts to the distinctive characteristics of each patient (weight, height, gait cycle). The primary objective of this research is to enhance the performance and longevity of prosthetic devices by improving their fatigue strength. The evaluation of load distribution on the prosthetic device, facilitated by FEM simulations, anticipates a substantial augmentation in the useful life of the prosthetic system. This research holds promise as a notable advancement in prosthetic technology, offering a more efficacious treatment option for patients suffering from joint arthritis. The aim of this research is to make meaningful contributions to the enhancement of patient quality of life and the long-term performance of prosthetic devices
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
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
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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