The Hypothetical witness in Gorgias and Antiphon

The paper below focuses on the shadowy figure of the hypothetical witness found in two mock-forensic works of the late 5th century: Gorgias’ Defence of Palamedes and Antiphon’s First Tetralogy. I argue that these witnesses, who only exist within the εἰκός arguments found in these speeches, are consistently characterized in impersonal ways, as individuals with knowledge pertinent to the resolution of the case. The issue of their will is also broached, particularly in last rebuttal speech of the First Tetralogy. Though such witnesses, being logical figments, could never appear in court, their characterization sheds important light on the ancient Greek notion of ‘witnessing’. Indeed, the very ability of Gorgias and Antiphon to deploy such arguments shows that witnessing was, at least in this cases, not thought to be tied to the witness’s prestige or character which remain entirely undefined. Rather, their characterization of a ‘witness’ as an individual who knows and who is motivated to testify implies that these were the features thought to fundamental to witnesses, whether real or fictive

Elastic constants of 3-, 4- and 6-connected chiral and anti-chiral honeycombs subject to uniaxial in-plane loading

Finite Element models are developed for the in-plane linear elastic constants of a family of honeycombs comprising arrays of cylinders connected by ligaments. Honeycombs having cylinders with 3, 4 and 6 ligaments attached to them are considered, with two possible configurations explored for each of the 3- (trichiral and anti-trichiral) and 4- (tetrachiral and anti-tetrachiral) connected systems. Honeycombs for each configuration have been manufactured using rapid prototyping and subsequently characterised for mechanical properties through in-plane uniaxial loading to verify the models. An interesting consequence of the family of 'chiral' honeycombs presented here is the ability to produce negative Poisson's ratio (auxetic) response. The deformation mechanisms responsible for auxetic functionality in such honeycombs are discussed

Pathophysiological mechanism of post-lobectomy air leaks

Background: Air leak post-lobectomy continues to remain a significant clinical problem, with upper lobectomy associated with higher air leak rates. This paper investigated the pathophysiological role of pleural stress in the development of post-lobectomy air leak.Methods: Preoperative characteristics and postoperative data from 367 consecutive video assisted thoracic surgery (VATS) lobectomy resections from one centre were collected prospectively between January 2014 and March 2017. Computer modelling of a lung model using finite element analysis (FEA) was used to calculate pleural stress in differing areas of the lung.Results: Air leak following upper lobectomy was significantly higher than after middle or lower lobectomy (6.3% versus 2.5%, P=0.044), resulting in a significant six-day increase in mean hospital stay, P=0.004. The computer simulation model of the lung showed that an apical bullet shape was subject to eightyfold higher stress than the base of the lung model.Conclusions: After upper lobectomy, the bullet shape of the apex of the exposed lower lobe was associated with high pleural stress, and a reduction in mechanical support by the chest wall to the visceral pleura due to initial post-op lack of chest wall confluence. It is suggested that such higher stress in the lower lobe apex explains the higher parenchymal air leak post-upper lobectomy. The pleural stress model also accounts for the higher incidence of right-sided prolonged air leak post-resection.peer-reviewe

Different Deformation Mechanisms Leading to Auxetic Behavior Exhibited by Missing Rib Square Grid Structures

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordAn extensive investigation is carried out on the missing rib square grid structure using finite element simulations. This showed that, in the cases considered in this study, the type of deformation is primarily dependent on the ratio of the thickness of different ribs with the structure behaving like an anti-tetrachiral at particular ratios. The analysis also showed that the ability of the structure to deform predominantly through the bending of the ligament allows it to achieve much more negative values of the Poisson's ratio than previously reported. Confirmation of the numerical results is obtained through experimental methods involving the 3D printing of representative structures which are subsequently subjected to compression.European Regional Development Fun

Fracture properties characterization of nuclear fuel using micro-cantilever bending

International audienc

On the Mechanical Properties of Graphyne, Graphdiyne, and Other Poly(Phenylacetylene) Networks

This is the author accepted manuscript. The final version is available from Wiley via the DOI in this recordWe simulate, analyse and compare the mechanical properties of a number of molecular sheet-like systems based on fully substituted, penta-substituted, tetra-substituted and tri-substituted poly(phenylacetylene) using static force-field based methods. The networks are modeled in a 3D environment with and without inter-layer interactions in analogy to graphite and graphene respectively. It is shown that by varying the type of substitution and the length of the acetylene chain, one may control the mechanical properties of such systems. In particular, it is shown that poly(phenylacetylene) systems can be specifically designed to exhibit negative Poisson's ratio, and that the stiffness can be controlled in an independent manner from the Poisson's ratios. This is significant as it highlights the fact that such systems can be tailored to exhibit a particular set of mechanical properties.The research work disclosed in this publication is funded by the ENDEAVOUR Scholarship Scheme (Malta). The scholarship may be part-financed by the European Union − European Social Fund (ESF) under Operational Programme II − Cohesion Policy 2014–2020, “Investing in human capital to create more opportunities and promote the well being of society.” JNG acknowledges the support of the University of Malta research grant