456 research outputs found
Sulla lettura del Fedone nella ‘Quarta Accademia’ (con riflessioni sulla composizione dell’Assioco pseudoplatonico)
No full textFew years ago, William Stull has persuasively examined Cicero’s peculiar reading of Plato’s Phaedo in Tusculans i (Reading the Phaedo in Tusculan Disputations 1, «Classical Philology», cvii, pp. 38-52). This article aims to show that Stull’s results can be interpreted not as Cicero’s personal reading of Plato’s Phaedo, but as his personal reinterpretation of a certain ‘hermeneutic approach’ to the Phaedo, which had been probably developed in the Academy led by Philo of Larissa, Cicero’s Academic master. Besides other reasons, this hypothesis is supported by the impressive intertextual play existing between the pseudo-platonic Axiochus and Tusculans i, as well as between these two dialogues and the Phaedo. In the ‘Appendix’ the author discusses the recent article by Francesco Verde (Filone di Larissa e l’Assioco, «Elenchos», xlii.1, 2021, pp. 199-208) dealing with A. Beghini, [Platone], Assioco, saggio introduttivo, edizione critica, traduzione e commento, Baden-Baden, Academia Verlag, 2020
Towards a Reliable Uncertainty Quantification in Residual Stress Measurements with Relaxation Methods: Finding Average Residual Stresses is a Well-Posed Problem
No full textBackground: In a previous work, the problem of identifying residual stresses through relaxation methods was demonstrated to be mathematically ill-posed. In practice, it means that the solution process is affected by a bias-variance tradeoff, where some theoretically uncomputable bias has to be introduced in order to obtain a solution with a manageable signal-to-noise ratio.
Objective: As a consequence, an important question arises: how can the solution uncertainty be quantified if a part of it is inaccessible? Additional physical knowledge could—in theory—provide a characterization of bias, but this process is practically impossible with presently available techniques.
Methods: A brief review of biases in established methods is provided, showing that ruling them out would require a piece of knowledge that is never available in practice. Then, the concept of average stresses over a distance is introduced, and it is shown that finding them generates a well-posed problem. A numerical example illustrates the theoretical discussion.
Results: Since finding average stresses is a well-posed problem, the bias-variance tradeoff disappears. The uncertainties of the results can be estimated with the usual methods, and exact confidence intervals can be obtained.
Conclusions: On a broader scope, we argue that residual stresses and relaxation methods expose the limits of the concept of point-wise stress values, which instead works almost flawlessly when a natural unstressed state can be assumed, as in classical continuum mechanics (for instance, in the theory of elasticity). As a consequence, we are forced to focus on the effects of stress rather than on its point-wise evaluatio
Analysis of the contact between cubic profiles
No full textThe contact between cubic profiles with continuous relative curvatures has been analyzed and solutions in closed form were obtained for both symmetric and non-symmetric conditions. Analytical solutions have allowed a complete parametric study to be performed, showing the effects of the gradient of relative curvature. The accuracy of approximate 'equivalent' Hertzian solutions has been verified
Fine increment hole-drilling method for residual stress measurement, proposal of a calibrating apparatus
No full textHole drilling is one of the most widely used technique for residual stress measurements, due to its precision and low cost. Standard ASTM E 837 is limited to the uniform distribution of residual stresses, whereas it is well known that residual stresses usually feature high gradient along the depth, particularly if residual stresses are induced by surface treatments such us shot peening. The incremental hole-drilling method can be used to evaluate the not-uniform residual stress distribution as shown by Schajer. The strain measurement is repeated at different hole depths to achieve information on the residual stress gradient, from relaxed surface strain. Influence functions for the incremental hole drilling are proposed by Beghini and Bertini by which the relaxed strain can be evaluated analytically if the residual stress distributions are known for any kind of rosette, hole diameter and elastic material. Valentini has developed an apparatus able to produce fine increment hole drilling, by means of a high speed air turbine drill automatically controlled. Valentini et al. used the appartatus to experimentally show the effects on residual stresses measurement by the hole drilling such as eccentricity and sequence of increments steps
An application of the weight function technique to inclined surface cracks under rolling contact fatigue, assessment and parametric analysis
No full textThis paper proposes the use of the weight function technique to calculate mode I and mode II stress intensity factors for a shallow surface crack typical of rolling contact fatigue, that experiences the detrimental effects of the pressurization of lubricating fluid. The weight function technique was able to easily take the pressurization into account just by adding the pressure term to the nominal stress component which is then integrated. The crack closure was also modeled by introducing an assumption for the distribution of the contact pressure on the crack face. The results were validated with the literature data and finite element analyses. Parametric simulations were performed showing that mode I and mode II stress intensity factors strongly depend on the crack angle with respect to the surface, and almost linearly on the size of the crack. In addition, the proposed algorithm was able to include any residual stress distribution. Compressive residual stress hinders pressurization and promotes the crack closure. This effect was parametrically investigated and it was found that cracks, and especially small ones, can even remain closed, with the opening effect of the pressurization completely suppressed
Nunc age . . . expediam: A Didactic Introductory Construction in Virgil’s Poetry
No full textThe present paper analyses a didactic three-part construction (henceforth D3C), composed of nunc, age and a first person singular commissive and metacommunicative
verbum dicendi. The D3C is present three times in Virgil’s poetry: once
in the Georgics and twice in the Aeneid. This study aims to consider each element from a linguistic, sociolinguistic, and pragmatic point of view, paying special attention to context and genre. Moreover, the D3C and its variants are studied in a comparative perspective along the literary and non-literary testimonia both latina and graeca of Antiquity, in order to identify possible literary models
Affermare l'immortalità dell'anima: il testo dell'Assioco tra Academici e Platonici
No full textAt the end of the Axiochus Socrates vigorously states that the soul is immortal (τοῦτο μόνον ἐμπέδως οἶδα ὅτι ψυχὴ ἅπασα ἀθάνατος· ἡ δὲ ἐκ τοῦδε τοῦ χωρίου μετασταθεῖσα καὶ ἄλυπος). However, this statement is in contrast with Socrates’ previous profession of ignorance in such matters. This contradiction raises the suspicion that the text is corrupted and possibly interpolated by a dogmatic Platonist. For this reason the author attempts the correction τοῦτο μόνον ἐμπέδως οἶδα ὅτι, ψυχὴ ἅπασα ἀθάνατος, [ἡ δὲ] ἐκ τοῦδε τοῦ χωρίου μετασταθεῖσα καὶ ἄλυπος. The XVIth century case of Étienne Dolet is a clear example of the ideological tensions that this dialogue could give rise t
Affermare l’immortalità dell’anima: il testo dell’Assioco tra Academici e Platonici
No full textAt the end of the Axiochus Socrates vigorously states that the soul is immortal (τοῦτο μόνον ἐμπέδως οἶδα ὅτι ψυχὴ ἅπασα ἀθάνατος· ἡ δὲ ἐκ τοῦδε τοῦ χωρίου μετασταθεῖσα καὶ ἄλυπος). However, this statement is in contrast with Socrates’ previous profession of ignorance in such matters. This contradiction raises the suspicion that the text is corrupted and possibly interpolated by a dogmatic Platonist. For this reason the author attempts the correction τοῦτο μόνον ἐμπέδως οἶδα ὅτι, <εἰ> ψυχὴ ἅπασα ἀθάνατος, [ἡ δὲ] ἐκ τοῦδε τοῦ χωρίου μετασταθεῖσα καὶ ἄλυπος. The XVIth century case of Étienne Dolet is a clear example of the ideological tensions that this dialogue could give rise to
La bellezza di Teosseno, ipotesi interpretativa di Pindaro fr. 123, 13-5 Maehler
No full textPartendo dalla definizione del valore di καί in Pind., fr. 123, 13 Maehler ci si propone di spiegare l’espressione ‘persino a Tenedo’ come un’allusione alle competizioni di bellezza femminile che avevano luogo, secondo le testimonianze antiche, sull’isola. Il senso così ottenuto consente di recuperare un aspetto della lode della bellezza di Teosseno e, contemporaneamente, di difendere la lezione trádita.Defining the function of the particle καί in Pind., fr. 123, 13 Maehler the author explains the expression ‘even in Tenedos’ as an allusion to the female beauty contests which, according to ancient witnesses, took place on the island. The meaning so obtained underlines a rhetoric mean to praise the young Theoxenus and lets us defend the reading of the manuscripts
CORTE DI GIUSTIZIA DELL’UNIONE EUROPEA, IV SEZIONE, 27 MARZO 2014, CAUSA C-565/12 (PRE- SIDENTE DI SEZIONE L. BAY LARSEN; GIUDICI M. SAFJAN; J. MALENOVSKÝ, A. PRECHAL, RELATO- RE K. JÜRIMÄE - LCL LE CRÉDIT LYONNAIS SA - AVV. C. VEXLIARD) - FESIH KALHAN.
No full textIl commento alla sentenza si propone di illustrare la tematica del merito creditizio e le conseguenze previste per la sua violazione sul profilo degli interessi. In particolare, si ha riguardo all'obbligo precontrattuale del creditore di valutare la solvibilità del debitore consultando una banca dati pertinente. L'attenzione è all'ordinamento francese che disciplina tale aspetto nel codice monetario e finanziario
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