Experimental Investigation on the Fracture Energy and Mechanical Behaviour of Hemp and Flax Fibre FRC Compared to Polypropylene FRC

Natural fibre reinforced concrete is been studied for many years as a more sustainable option to current reinforced concrete used in industry. The most common fibre materials currently adopted are steel, glass and synthetic fibres. Apart from the high oxidation and cost, their environmental impact is a serious issue as they are petroleum-based materials. This study assesses the feasibility of replacing polypropylene fibre with hemp and flax fibres. According to the inventory of carbon and energy (ICE) the embodied energy of polypropylene (PP) is 95.4MJ/kg and the embodied carbon is 4.98kgCO2/kg during its lifetime. It represents approximately 3 times more than the estimated values for vegetable fibres. For this, Different concrete mixtures reinforced by 0.5% to 1.0% of hemp, flax and polypropylene fibres were tested, and their post-crack flexural tensile strength, elastic’s modulus, compressive strength and fracture energy were evaluated. The mixtures containing hemp fibres presented properties equivalent to those containing polypropylene under the same proportion. Although both compressive and tensile strength were reduced for the mixes containing flax fibres, the Young’s modulus was 49% smaller and could be an interesting approach for applications that require better elasticity from the concrete, such as industrial floors and structures that may be submitted to impact.

Binary Silicone Elastomeric Systems with Stepwise Crosslinking as a Tool for Tuning Electromechanical Behavior

Interpenetrating polymer networks (IPNs) represent an interesting approach for tuning the properties of silicone elastomers due to the possible synergism that may occur between the networks. A new approach is presented, which consists of mixing two silicone-based networks with different crosslinking pathways; the first network being cured by condensation route and the second network by UV curing. The networks were mixed in different ratios and the resulted samples yield good mechanical properties (improved elongations, up to 720%, and Young’s modulus, 1 MPa), thermal properties (one glass transition temperature, ~−123 °C), good dielectric strength (~50 V/μm), and toughness (63 kJ/m3).

CO Oxidation Capabilities of La- and Nd-Based Perovskites

Catalytic tests to assess the performance of mixed perovskite-type oxides (La0.9Ca0.1FeO3-δ, La0.6Ca0.4FeO3-δ, Nd0.9Ca0.1FeO3-δ, Nd0.6Ca0.4FeO3-δ, Nd0.6Ca0.4Fe0.9Co0.1O3-δ, Nd0.6Ca0.4Fe0.97Ni0.03O3-δ, and LSF) with respect to CO oxidation are presented as well as characterization of the materials by XRD and SEM. Perovskites are a highly versatile class of materials due to their flexible composition and their ability to incorporate dopants easily. CO oxidation is a widely used “probe reaction” for heterogeneous catalysts. In this study, it is demonstrated how tuning the composition of the catalyst material (choice of A-site cation, A-site and B-site doping) greatly influences the activity. Changing the A-site cation to Nd3+ or increasing the concentration of Ca2+ as A-site dopant improves the performance of the catalyst. Additional B-site doping (e.g., Co) affects the performance as well—in the case of Co-doping by shifting ignition temperature to lower temperatures. Thus, perovskites offer an interesting approach to intelligent catalyst design and tuning the specific properties towards desired applications.

Screening of coformers for quercetin cocrystals through mechanochemical methods

Quercetin (QUE) is a nutraceutical compound that exhibits pharmacological properties such as antioxidant, cardioprotective, anti-ulcer, and anti-inflammatory effects. Although QUE is well-known for its benefits, its efficacy is limited due to low solubility. Thus, cocrystallization acts as an interesting approach to improve the solubility�among other properties�of this compound. In this work, cocrystallization screening was applied through neat grinding (NG) and liquid-assisted grinding (LAG), in which QUE and four cocrystal formers (benzamide,�picolinamide, isonicotinamide, and pyrazinoic acid) were tested. The precursors and QUE-coformer systems were characterized using thermoanalytical techniques (TG-DTA), X-ray powder diffraction (XRPD), and Fourier transform infrared (FTIR) spectroscopy. The results showed the formation of QUE cocrystals with picolinamide and isonicotinamide coformers in a 1:1 stoichiometric ratio. Furthermore, although coformers are isomers, spectroscopic and thermal data suggest that the supramolecular synthons involved in cocrystallization are different.

The Learning Style of Gamers

The use of gamification has shown to be an interesting approach to engage users in MOOCs. In this context, different game strategies, elements, and mechanics are applied to help to improve the teaching/learning process. When designing teaching/learning methods, teachers must take into account both gamification techniques and learning styles in order to encourage students and to improve their learning performance, respectively. However, while applying gamification and at the same time keep taking into account the corresponding learning styles, we may find some kinds of incompatibilities. Thus, what this chapter covers is the conducted experimental analysis aimed at exploring the viability of merging gamer's profiles and learning styles in a single multidimensional user profile. The obtained results expose that, with this approach, we are able to identify groups of students so that, while designing teaching/learning methods, we can take into account both learning styles to improve the learning performance and gamification techniques to motivate and encourage the student.

Study of the Mechanical Properties of Wood under Transverse Compression Using Monto Carlo Simulation-Based Stochastic FE Analysis

Wood is an anisotropic material, the mechanical properties of which are strongly influenced by its microstructure. In wood, grain compression strength and modulus are the weakest perpendicular to the grain compared to other grain directions. FE (finite element) models have been developed to investigate the mechanical properties of wood under transverse compression. However, almost all existing models were deterministic. Thus, the variations of geometry of the cellular structure were not considered, and the statistical characteristic of the mechanical property was not involved. This study aimed to develop an approach to investigate the compression property of wood in a statistical sense by considering the irregular geometry of wood cells. First, the mechanical properties of wood under radial perpendicular to grain compression was experimentally investigated, then the statistical characteristic of cell geometry was extracted from test data. Finally, the mechanical property of wood was investigated using the finite element method in combination with the Monte Carlo Simulation (MCS) techniques using randomly generated FE models. By parameter sensitivity analysis, it was found that the occurrence of the yield points was caused by the bending or buckling of the earlywood axial tracheid cell wall in the tangential direction. The MCS-based stochastic FE analysis was revealed as an interesting approach for assessing the micro-mechanical performance of wood and in assisting in understanding the mechanical behavior of wood based on its hierarchical structure.

Knowledge Gaps in the Fetal to Neonatal Transition of Infants With a Congenital Diaphragmatic Hernia

Clinical research for infants born with a congenital diaphragmatic hernia (CDH) has until recently mainly focused on advances in prenatal and postnatal treatment. However, during the early perinatal transition period there are major physiological adaptations. For most infants these changes will happen uneventfully, but for CDH infants this marks the beginning of serious respiratory complications. In recent years, there is emerging evidence that the clinical management during the perinatal stabilization period in the delivery room may influence postnatal outcomes. Herein, we discuss major knowledge gaps and novel concepts that aim to optimize fetal to neonatal transition for infants with CDH. One such novel and interesting approach is performing resuscitation with an intact umbilical cord, the efficacy of this procedure is currently being investigated in several clinical trials. Furthermore, close evaluation of neonatal physiological parameters in the first 24 h of life might provide early clues concerning the severity of lung hypoplasia and the risk of adverse outcomes. We will provide an overview of trending concepts and discuss potential areas for future research.

Book Review: Robert J. Barro and Rachel M. McCleary, The Wealth of Religions: The Political Economy of Believing and Belonging, Princeton, NJ: Princeton University Press, 2019.

A preface, eight chapters, notes, a bibliography, and an index are what constitute Barro and McCleary’s in-depth analysis of the “wealth” of religions. The book’s title is very attractive, and at the same time quite provocative, as politics, economics and religions are widely debated topics in most societies these days, but people remain reserved to tackle certain aspects, in particular the link between money, markets and religious beliefs and belonging. Bringing together the views of an economist, Barro, and a moral philosopher, McCleary, leads to an interesting approach to religion as different from a social construct, the main idea upon which reflecting and debating religion has been based upon for years, if not centuries.

Lived and perceived space during lock-down in a sensitive map approach

The first lock-down in France due to the Covid-19 pandemic happened during spring 2020. It meant restrictions for everyone regarding reachable space and possible time length outside home. The seminar of sensitive mapping taking place in École des hautes études en sciences sociales (EHESS) went online and proposed an exercise to investigate the consequences of these statutory restrictions on individual lived and perceived space. The defined protocol of the exercise was based on the framework of the sensitive map approach. This approach adapts the principles of conventional cartography so that to favour personal information selection and design. Each participant of the seminar had the task to map their space. Displayed information should concern meaningful elements from their spatial environment. Other targeted information was sensitive information including emotions, feelings, and opinions as well as perceived elements from the five senses. The resulted map corpus offers diverse mapping creations. Each map contains several graphic items. Items are mainly cartographical displays enriched with non-cartographical drawings, pictures, photos, records, charts. Techniques were mixed: pen, fabrics, computer-based. The themes of displayed elements are about spatially-stable features like the dwelling, buildings remained open, green spaces, and about ephemeral and sensitive information like social interactions, people, perceived sounds, smells and feelings about the lock-down situation and the pandemic. Some maps have used or were inspired by topographic maps. Though in most maps, distances and topology are subjective. Sensitive mapping appeared as an interesting approach to collect individual testimonies and might be complementary to statistical studies.