Comparison of a Material Point Method and a Galerkin meshfree method for the simulation of cohesive-frictional materials

The simulation of large deformation problems, involving complex history-dependent constitutive laws, is of paramount importance in several engineering fields. Particular attention has to be paid to the choice of a suitable numerical technique such that reliable results can be obtained. In this paper, a Material Point Method (MPM) and a Galerkin Meshfree Method (GMM) are presented and verified against classical benchmarks in solid mechanics. The aim is to demonstrate the good behavior of the methods in the simulation of cohesive-frictional materials, both in static and dynamic regimes and in problems dealing with large deformations. The vast majority of MPM techniques in the literature are based on some sort of explicit time integration. The techniques proposed in the current work, on the contrary, are based on implicit approaches, which can also be easily adapted to the simulation of static cases. The two methods are presented so as to highlight the similarities to rather than the differences fromPeer ReviewedPostprint (published version

Comparison of a Material Point Method and a Galerkin Meshfree Method for the Simulation of Cohesive-Frictional Materials

The simulation of large deformation problems, involving complex history-dependent constitutive laws, is of paramount importance in several engineering fields. Particular attention has to be paid to the choice of a suitable numerical technique such that reliable results can be obtained. In this paper, a Material Point Method (MPM) and a Galerkin Meshfree Method (GMM) are presented and verified against classical benchmarks in solid mechanics. The aim is to demonstrate the good behavior of the methods in the simulation of cohesive-frictional materials, both in static and dynamic regimes and in problems dealing with large deformations. The vast majority of MPM techniques in the literatrue are based on some sort of explicit time integration. The techniques proposed in the current work, on the contrary, are based on implicit approaches, which can also be easily adapted to the simulation of static cases. The two methods are presented so as to highlight the similarities to rather than the differences from "standard" Updated Lagrangian (UL) approaches commonly employed by the Finite Elements (FE) community. Although both methods are able to give a good prediction, it is observed that, under very large deformation of the medium, GMM lacks robustness due to its meshfree natrue, which makes the definition of the meshless shape functions more difficult and expensive than in MPM. On the other hand, the mesh-based MPM is demonstrated to be more robust and reliable for extremely large deformation cases

Premorbid intelligence of inpatients with different psychiatric diagnoses does not differ

The diagnostic specificity of poor premorbid intelligence is controversial. We explored premorbid intelligence level in psychiatric patients with personality disorders, depressive disorders, bipolar disorders and schizophrenic disorders. 273 consecutively admitted patients and 81 controls were included in the study and tested with the ‘Test di Intelligenza Breve’, an Italian adaptation of the National Adult Reading Test. Significant differences between the clinical samples and the control subjects were found but not among the 4 clinical groups. The observation of premorbid IQ deficits in subjects with diagnoses other than schizophrenia suggests a common vulnerability diathesis, which is most likely to have a neurodevelopmental basis

Combining biocontrol agents with different mechanisms of action in a strategy to control Botrytis cinerea on grapevine

The use of several microbial biocontrol agents to combat Botrytis cinerea, the causal agent of grey mould, has been studied. However, only a few microorganisms have been developed as biofungicides, which are currently used in some countries, mostly in organic farming. The main reason for the limited market uptake of microbial biofungicides is their debated variable efficacy. To cope with poor survival in the canopy, due to unfavourable environmental conditions or their intrinsic lower level of disease control compared to synthetic chemical fungicides, use of a mixture of two or more microorganisms with different environmental requirements and mechanisms of action has been proposed with contrasting results. However, their use in strategies involving calculated timing of the microbial biocontrol agents, taking into consideration their mechanism of action in relation to the epidemiology and pathogenesis of the disease, has never been attempted in relation to combating grey mould on grapes. The results of four years of trials in three locations in Northern and Central Italy show that Trichoderma atroviride, Aureobasidium pullulans and Bacillus subtilis, applied at bunch-closure, veraison and pre-harvest, respectively, controlled B. cinerea on bunches very satisfactorily, and the results did not differ from those obtained with a strategy combining the three biofungicides, applied at the aforementioned stages. Colonisation of berries by each of the different microbial biocontrol agents at harvest time did not differ for individual treatments or when applied in the combined strategy, suggesting that the microorganisms did not negatively interfere with each other and that they may possibly occupy different ecological niches. The high level of efficacy of the tested biocontrol agents against grey mould can be explained with the relatively low-medium level of the disease, their integration with agronomic practices or the optimal timing of the treatment

Low Surface Energy Fluorocarbon Coatings Via Plasma Polymerization Process: Process Optimization and Protein Repellent Study

In the present study, low surface energy perfluorodecyl acrylate (PFDA) coatings and their copolymer coatings with diethylene glycol dimethyl ether (DEGDME) (i.e. PFDA-co-DEGDME) have been deposited through plasma enhanced chemical vapor deposition (PECVD) onto thermanox coverslips in a low pressure tubular inductively coupled RF plasma reactor. The influence of plasma parameters on surface chemical properties of the coatings were investigated by using fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), x-ray photoelectron spectroscopy (XPS) and water contact angle (WCA). The protein repellent properties of the plasma polymer coatings have been investigated using quartz crystal microbalance (QCM).JRC.DG.I.5-Nanobioscience

Antioxidant Properties of Lippia alba Essential Oil: A Potential Treatment for Oxidative Stress-Related Conditions in Plants and Cancer Cells

Lippia alba (Mill.) N.E.Br. ex Britton and P. Wilson is used in folk medicine of Central and South America for its biological activities: i.e., antifungal, antibacterial, antiviral, and anti-inflammatory. Based on ethnopharmacological information and the increasing interest in this species, this work aimed to test a possible wide use of its essential oil (EO) in pharmaceutical and horticultural applications. Therefore, we focused the attention on the antioxidant activity of the oil as a possible tool to overcome the oxidative stress in both applications. For this purpose, we have chosen three aggressive breast cancer cell lines and two horticultural species (Solanum lycopersicum L. and Phaseolus acutifolius L.) that are very sensitive to salt stress. We determined the antioxidant activity of L. alba EO through the quantification of phenols and flavonoids. Regarding tomato and bean plants under salt stress, L. alba EO was used for the first time as a seed priming agent to enhance plant salt tolerance. In this case, the seed treatment enhanced the content of phenolic compounds, reduced power and scavenger activity, and decreased membrane lipid peroxidation, thus mitigating the oxidative stress induced by salt. While in breast cancer cells the EO treatment showed different responses according to the cell lines, i.e., in SUM149 and MDA-MB-231 the EO decreased proliferation and increased antioxidant activity and lipid peroxidation, showing high cytotoxic effects associated with the release of lactate dehydrogenase, vice versa no effect was observed in MDA-MB-468. Such antioxidant activity opens a new perspective about this essential oil as a possible tool to counteract proliferation in some cancer cell lines and in horticulture as a seed priming agent to protect from oxidative damage in crops sensitive to salinity

A stabilized mixed implicit Material Point Method for non-linear incompressible solid mechanics

The final publication is available at Springer via http://dx.doi.org/10.1007/s00466-018-1647-9In this work a stabilized mixed formulation for the solution of non-linear solid mechanics problems in nearly-incompressible conditions is presented. In order to deal with high material deformation, an implicit Material Point Method is chosen. Such choice allows avoiding the classical limitations of the Finite Element Method, e.g., element tangling and extreme mesh distortion. The proposed mixed formulation, with displacement and pressure as primary variables, is tested through classical benchmarks in solid and geo-mechanics where a Neo-Hookean, a J2 and a Mohr-Coulomb plastic law are employed. Further, the stabilized mixed formulation is compared with a displacement-based formulation to demonstrate how the proposed approach gets better results in terms of accuracy, not only when incompressible materials are simulated, but also in the case of compressible ones.Peer ReviewedPostprint (author's final draft

Saoul comme une bourrique ou comme un polonais? Boire: une réflexion phraséologique et traductologique

The present communication is focused on the phrasemes referring to the act of Phrasis Diciembre 2019 39 “drinking”. They will be analysed according to three perspectives: the lexicographic, linguistic and translational ones. The starting point of our analysis will be the lexicographic research carried out through the electronic edition of the Petit Robert in order to explore its « phraseological nomenclature » and finally constitute a corpus on an onomasiological basis. In the second phase of our study, lexicographic results will be compared with a sample of available and up-to-date corpora data in order to highlight some preliminary observations on the historical evolutions and discourse patterns characterising our selected phrasemes. The third and final step of our research will aim at recognizing the French-Italian phrasemes which can be defined as translational equivalents (Baker, 2011; Salmon, 2003; Delisle 2000). Their frequency inside corpora as well as their phraseological co-texts will be related to discourse patterns specific to our equivalents.Les phrasèmes exprimant le sens ‘boire’ seront pris en compte de plusieurs points de vue: la lexicographie, l’analyse d’un échantillon des corpus disponibles en ligne et la traductologie. Premièrement, une recherche plein texte dans la dernière édition électronique du Petit Robert permettra d’explorer la “nomenclature phraséologique” du dictionnaire, afin de constituer un corpus d’expressions sur une base onomasiologique. Ensuite, nous vérifierons les résultats issus de l’analyse lexicographique par le biais d’une analyse exploratoire d’un échantillon de corpus en ligne, afin de proposer quelques premières remarques sur les traces des évolutions historiques et des dynamiques discursives qui intéressent les phrasèmes déjà répertoriés dans le dictionnaire. Enfin, nous identifierons les phrasèmes franco-italiens pouvant se définir comme équivalents traductionnels (Baker, 2011; Salmon et al., 2008; Delisle, 1993). Une comparaison de leur récurrence dans les corpus ainsi que l’observation de leurs co-textes nous permettront notamment de cibler les spécificités discursives de nos paires de phrasèmes.Les phrasèmes exprimant le sens ‘boire’ seront pris en compte de plusieurs points de vue: la lexicographie, l’analyse d’un échantillon des corpus disponibles en ligne et la traductologie. Premièrement, une recherche plein texte dans la dernière édition électronique du Petit Robert permettra d’explorer la “nomenclature phraséologique” du dictionnaire, afin de constituer un corpus d’expressions sur une base onomasiologique. Ensuite, nous vérifierons les résultats issus de l’analyse lexicographique par le biais d’une analyse exploratoire d’un échantillon de corpus en ligne, afin de proposer quelques premières remarques sur les traces des évolutions historiques et des dynamiques discursives qui intéressent les phrasèmes déjà répertoriés dans le dictionnaire. Enfin, nous identifierons les phrasèmes franco-italiens pouvant se définir comme équivalents traductionnels (Baker, 2011; Salmon et al., 2008; Delisle, 1993). Une comparaison de leur récurrence dans les corpus ainsi que l’observation de leurs co-textes nous permettront notamment de cibler les spécificités discursives de nos paires de phrasèmes