Effects of curing on the hydro-mechanical behaviour of cement-bentonite mixtures for cut-off walls

Cement-bentonite cut-off walls are commonly employed in geoenvironmental applications to limit ground water flow and pollutant transport. The wide diffusion of this artificial material in the current practice is not only due to its low permeability, but also to its simplicity of use. In this paper, experimental evidences about the role of curing on the hydro-mechanical behaviour of cement-bentonite mixtures are presented. Different curing times and curing conditions (representative for either water saturated or hydrocarbon polluted soils) have been considered, and their effects on both hydraulic conductivity and mechanical response in oedometer and triaxial conditions have been assessed. A unified hydro-mechanical framework, accounting for the changes of material fabric occurring with curing time and environment, is formulated. The hydraulic conductivity is very well predicted by a Kozeny-Carman like equation, whereas the mechanical behaviour is finely reproduced via an enhanced elastic–plastic constitutive model

Advanced turboprop multidisciplinary design and optimization within agile project

The present paper deals with the design, analysis and optimization of a 90 passengers turboprop aircraft with a design range of 1200 nautical miles and a cruise Mach number equal to 0.56. The prescribed aircraft is one of the use cases of the AGILE European project, aiming to provide a 3rd generation of multidisciplinary design and optimization chain, following the collaborative and remote aircraft design paradigm, through an heterogenous team of experts. The multidisciplinary aircraft design analysis is set-up involving tools provided by AGILE partners distributed worldwide and run locally from partners side. A complete design of experiment, focused on wing planform variables, is performed to build response surfaces suitable for optimization purposes. The goal of the optimization is the direct operating cost, subject to wing design variables and top-level aircraft requirements

An improved method for transport aircraft for high lift aerodynamic prediction

The aim of this work is the development of a methodology to predict lift characteristics for transport aircraft in the whole flight envelope, useful in the preliminary aircraft design stage. The purpose is an attempt to improve the classical methodologies for wing load distribution and lift prediction, considering the airfoils aerodynamic characteristics until stall and post stall conditions during the process, and modifying 2D characteristics in case of high lift devices to take into account 3D effects introduced by the devices themselves. The method is a modification of Nasa Blackwell procedure, capable to predict wing stall aerodynamic characteristics for both clean and flapped configuration. As far the high lift devices effect is concerned, the improved method works substituting clean airfoil aerodynamic characteristics with the flapped aerodynamics ones, and introducing a correction to evaluate the 3D effects induced by high lift devices geometrical discontinuities. The results of the developed method have been compared with CFD and experimental data showing good agreement, making available a fast and reliable method, useful in preliminary aircraft design

Factors associated with SARS-CoV-2 infection risk among healthcare workers of an italian university hospital

We report the results of a study on the cumulative incidence of SARS-CoV-2 infections in about 6000 workers of the University Hospital of Modena, Northern Italy, in the period March 2020–January 2021, and the relations with some individual and occupational factors. Overall, in healthcare workers (HCW) the cumulative incidence of COVID-19 during the period was 13.8%. Results confirm the role of overweight and obesity as significant risk factors for SARS-CoV-2 infection. Chronic respiratory diseases, including asthma, also proved to be significantly associated with the infection rate. Considering occupational factors, the COVID-19 risk was about threefold (OR: 2.7; 95% CI 1.7–4.5) greater in nurses and nurse aides than in non-HCW, and about double (OR: 1.9; 95% CI 1.2–3.2) in physicians. Interestingly, an association was also observed between infection risk and nightshifts at work (OR: 1.8; 95% CI 1.4–2.3), significantly related to the total number of shifts in the whole eleven-month period. Even if the vaccination campaign has now greatly modified the scenario of SARS-CoV-2 infections among HCW, the results of this study can be useful for further development of health and policy strategies to mitigate the occupational risk related to the new variants of coronavirus, and therefore the evolution of the pandemic

Disponibilidade e adoção de trigo biscoito no Rio Grande do Sul, no período de 2014 a 2019.

O trigo, um dos cereais mais cultivados no mundo, apresenta diversos usos e aptidões tecnológicas. No Brasil, o consumo de biscoitos é elevado, constituindo um importante nicho de mercado. Devido a condições climáticas e aspectos agronômicos de manejo, o Rio Grande do Sul (RS) se destaca pela grande potencialidade para produção de trigo biscoito. Assim, o objetivo do trabalho foi avaliar a disponibilidade e a adoção de cultivares de trigo com aptidão para a fabricação de biscoitos, no RS, no período de 2014 a 2019. A disponibilidade de cultivares para biscoito foi avaliada por meio de levantamento de todas as cultivares de trigo indicadas para o RS, em cada ano (safra agrícola), e identificação daquelas com perfil biscoito, segundo informações dos obtentores e da Comissão Brasileira de Pesquisa de Trigo e Triticale. A adoção das cultivares para biscoito foi avaliada com base nos dados anuais de área inscrita e de produção de sementes registrados pela Apassul. O número de cultivares de trigo biscoito indicadas para cultivo no RS variou de 7 (ano 2014) a 13 (anos 2017, 2018 e 2019). Contudo, os percentuais de área inscrita e de produção de sementes de trigo biscoito variaram, respectivamente, de 0,4% a 3,7% e de 0,4% a 4,3%, valores significativamente inferiores ao percentual de cultivares biscoito indicadas e muito aquém da demanda do mercado brasileiro para produção de biscoitos. Assim, são necessárias ações para incentivar a adoção/cultivo de trigo biscoito no RS. Palavras-chave: Triticum aestivum, Qualidade Tecnológica, Nicho de Mercado, Produção de Sementes, Cultivar

Non-perturbative Test of the Witten-Veneziano Formula from Lattice QCD

We compute both sides of the Witten-Veneziano formula using lattice techniques. For the one side we perform dedicated quenched simulations and use the spectral projector method to determine the topological susceptibility in the pure Yang-Mills theory. The other side we determine in lattice QCD with $N_f=2+1+1$ dynamical Wilson twisted mass fermions including for the first time also the flavour singlet decay constant. The Witten-Veneziano formula represents a leading order expression in the framework of chiral perturbation theory and we also employ leading order chiral perturbation theory to relate the flavor singlet decay constant to the relevant decay constant parameters in the quark flavor basis and flavor non-singlet decay constants. After taking the continuum and the SU$(2)$ chiral limits we compare both sides and find good agreement within uncertainties.Comment: 30 pages, 7 figures, version accepted for publicatio