Wrinkling in engineering fabrics: a comparison between two different comprehensive modelling approaches

We consider two ‘comprehensive’ modelling approaches for engineering fabrics. We distinguish the two approaches using the terms ‘semi-discrete’ and ‘continuum’, reflecting their natures. We demonstrate a fitting procedure, used to identify the constitutive parameters of the continuum model from predictions of the semi-discrete model, the parameters of which are in turn fitted to experimental data. We, then, check the effectiveness of the continuum model by verifying the correspondence between semi-discrete and continuum model predictions using test cases not previously used in the identification process. Predictions of both modelling approaches are compared against full-field experimental kinematic data, obtained using stereoscopic digital image correlation techniques, and also with measured force data. Being a reduced order model and being implemented in an implicit rather than an explicit finite-element code, the continuum model requires significantly less computational power than the semi-discrete model and could therefore be used to more efficiently explore the mechanical response of engineering fabrics

A nonlinear Lagrangian particle model for grains assemblies including grain relative rotations

International audienceWe formulate a discrete Lagrangian model for a set of interacting grains, which is purely elastic. The considered degrees of freedom for each grain include placement of barycenter and rotation. Further, we limit the study to the case of planar systems. A representative grain radius is introduced to express the deformation energy to be associated to relative displacements and rotations of interacting grains. We distinguish inter‐grains elongation/compression energy from inter‐grains shear and rotations energies, and we consider an exact finite kinematics in which grain rotations are independent of grain displacements. The equilibrium configurations of the grain assembly are calculated by minimization of deformation energy for selected imposed displacements and rotations at the boundaries. Behaviours of grain assemblies arranged in regular patterns, without and with defects, and similar mechanical properties are simulated. The values of shear, rotation, and compression elastic moduli are varied to investigate the shapes and thicknesses of the layers where deformation energy, relative displacement, and rotations are concentrated. It is found that these concentration bands are close to the boundaries and in correspondence of grain voids. The obtained results question the possibility of introducing a first gradient continuum models for granular media and justify the development of both numerical and theoretical methods for including frictional, plasticity, and damage phenomena in the proposed model

Consumo voluntário e desempenho de ovinos submetidos a dietas contendo diferentes níveis de feno de maniçoba.

O objetivo do presente trabalho foi determinar o efeito de níveis crescentes de feno de maniçoba na dieta de carneiros confinados, sobre o consumo de nutrientes e o ganho de peso dos animais

Fournier's gangrene and intravenous drug abuse. An unusual case report and review of the literature

Fournier's gangrene is a potentially fatal emergency condition characterized by necrotizing fasciitis and supported by an infection of the external genital, perineal and perianal region, with a rapid and progressive spread from subcutaneous fat tissue to fascial planes.In this case report, a 52-year-old man, with a history of hepatitis C-virus (HCV)-related chronic liver disease and cocaine use disorder for which he was receiving methadone maintenance therapy, was admitted to the Emergency Department with necrotic tissue involving the external genitalia.Fournier's gangrene is usually due to compromised host immunity, without a precise cause of bacterial infection; here it is linked to a loco-regional intravenous injection of cocaine. A multimodal approach, including a wide surgical debridement and a postponed skin graft, was needed. Here we report this case, with a narrative review of the literature

Effects of feeding frequency on the productive performance of different tilapia strains.

This study was conducted during 251 days from April 13th to December 20th in 2010, and it aimed the evaluation of zootechnical performance of three tilapia strains submitted to two feeding frequencies, fed twice a day (2x) and fed once a day (1x)

Differential Midgut Attachment of Leishmania (Viannia) braziliensis in the Sand Flies Lutzomyia (Nyssomyia) whitmani and Lutzomyia (Nyssomyia) intermedia

The interaction between Leishmania and sand flies has been demonstrated in many Old and New World species. Besides the morphological differentiation from procyclic to infective metacyclic promastigotes, the parasite undergoes biochemical transformations in its major surface lipophosphoglycan (LPG). An upregulation of β-glucose residues was previously shown in the LPG repeat units from procyclic to metacyclic phase in Leishmania (Viannia) braziliensis, which has not been reported in any Leishmania species. LPG has been implicated as an adhesion molecule that mediates the interaction with the midgut epithelium of the sand fly in the Subgenus Leishmania. These adaptations were explored for the first time in a species from the Subgenus Viannia, L. (V.) braziliensis with its natural vectors Lutzomyia (Nyssomyia) intermedia and Lutzomyia (Nyssomyia) whitmani. Using two in vitro binding techniques, phosphoglycans (PGs) derived from procyclic and metacyclic parasites were able to bind to the insect midgut and inhibit L. braziliensis attachment. Interestingly, L. braziliensis procyclic parasite attachment was ∼11-fold greater in the midgut of L. whitmani than in L. intermedia. The epidemiological relevance of L. whitmani as a vector of American Cutaneous Leishmaniasis (ACL) in Brazil is discussed

Avaliação dos aspectos clínicos e parasitológicos de cordeiros em capim-aruana irrigado e adubado com nitrogênio sob taxa lotação intermitente.

Este trabalho objetivou avaliar os aspectos clínicos e parasitológicos de ovinos mantidos em pastejo irrigado e rotativo de "P. maximum cv. Aruana" adubado com quatro doses de nitrogênio: 75 kg/ha, 275 kg/ha, 475 kg/ha e 675 kg/ha. Foi utilizado o método de pastejo rotativo com taxa de lotação intermitente, sendo utilizados seis carneiros tester por piquete, perfazendo um total de 72 animais tester. Foi utilizado o método de vermifugação mensal. As contagens do número de ovos por grama de fezes (OPG) foram realizadas m,ensalmente e sete dias após cada aplicação anti-helmíntica. Foram realizadas avaliações da cor ou palidez da mucosa ocular a cada quinze dias segundo o método FamachaÓ. Com o uso do anti-helmíntico a base de closantel, as eficácias de redução do OPG obtidas foram superiores a 85%. Após o início das aplicações anti-helmínticas, a média do OPG variou entre 737 a 355 ovos. A coloração da mucosa ocular mostrou-se sadia (graus 1 ou 2) em 47,5% dos animais, todavia sem diferença significativa (P>0,05) entre os tratamentos. Foram identificados uma média de 10,3% de animais anêmicos (graus 4 ou 5). Foi evidenciado aumento significado (P<0,05) no OPG4 e OPG5 na adubação nitrogenada de 75 kg/ha, embora sem haver animais anêmicos. A vermifugação mensal dos cordeiros controlou os níveis de infestação dos nematóideos gastrintestinais, mantendo os animais com mucosa ocular bem-corada e baixo número de OPG