ALBERT

Description: Nowadays, construction, maintenance, reparation, rehabilitation, retrofitting, and demolition from infrastructure and buildings generate large amounts of urban waste, which usually are inadequately disposed due to high costs and technical limitations. On the other hand, the increasing demand for natural aggregates for concrete production seriously affects mountains and rivers as they are the source of these nonrenewable goods. Consequently, the recycling of aggregates for concrete is gaining attention worldwide as an alternative to reduce the environmental impacts caused by the extraction of nonrenewable goods and disposal of construction and demolition waste (C&DW). Therefore, this article describes the effect on the mechanical properties of new concrete using recycled aggregates obtained from old paving stones. Results show that replacing 50% by weight of the fine and coarse aggregate fractions in concrete with recycled aggregate does not meaningfully affect its mechanical behavior, making the use of recycled aggregates in new precast paving stones possible. Therefore, the latter can reduce environmental impacts and costs for developing infrastructure and building projects.

Description: Shea trees grow across 4 million km2 of sub-Saharan Africa. Shea parklands provide a sustainable source of edible fat (shea butter) that, in terms of volume, is currently second only to cocoa butter as a vegetal source of stearic acid in the multi-billion dollar chocolate and cosmetic sectors. However, in terms of international trade, shea has been opaque to consumers of edible products (where the majority of shea exports end their global journey) and actually only well-known in western markets as a cosmetic ingredient. The millions of women collectors have been disconnected from global supply chains, as the majority of their sheanuts are factory processed, supplied by traders who, in many cases, do not understand quality issues nor share knowledge with their village-based collectors—this is the “Paradox of paradoxa”. This review provides the background to this issue by contextualizing the industry and describing how weak post-harvest quality control impacts the shea supply chain. The paper then explains how this knowledge was incorporated into a 3D animation available for free transmission to rural African audiences and viewing on portable devices like video capable mobile phones. This tool offers the potential of low-cost multiple benefits to users, which we term here a win-cubed [win3] opportunity, where women collectors can receive free knowledge of using less resources to produce higher quality shea kernels which in turn offer higher extraction yields, lowering production costs, of a better and more marketable product.

Description: Sustainable fishing includes the socioeconomic status of fishers. We combined empirical quality of life (QOL) and subjective lived experiences methods to explore the social sustainability of artisanal fishers in five fishery collectives along the coast of Jalisco, Mexico, where the average daily income is slightly above the poverty level. The QOL scores were also related to annual catch and incomes within each collective. A QOL index is used in this study that combines importance and achievement ratings scores; the results are indicative of an acceptable QOL for fishermen. The concept of lived experiences, incorporating aspects of life relating to Mind, Body, Work and People was explored through interviews with 12 fishers. The QOL data revealed that family and friends are important indicators related to positive QOL reported by the sample, while economic indicators were not important. Although four of the five collectives perceived that the future looks worse than the present and past, there was limited correlation between catch or income and QOL. However, while the lived experiences exercise in part supported the QOL findings, in that People was the most important dimension for almost all of the fishers interviewed, negative economic gaps related to poor catches and incomes were prevalent in the Mind and Work dimensions. The findings suggest that to understand the socioeconomic component of sustainable fisheries, both of these approaches should be considered, as they can illuminate different aspects of fishers’ lives that need to be considered during the development of fisheries’ management policies.

Description: Coastal fisheries contribute to global food security, since fish are an important source of protein for many coastal communities in the world. However, they are constrained by problems, such as weak management of fisheries and overfishing. Local communities perceive that they are fishing less, as in other fisheries in the world. The aim of this study was to evaluate the fisheries sustainability in the Jalisco coast through the fishing footprint, or fishprint (FP), based on the primary productivity required (PPR) and the appropriated surface by the activity (biocapacity). The total catch was 20,448.2 metric tons from 2002–2012, and the average footprint was calculated to be 65,458 gha/year, a figure that quadrupled in a period of 10 years; the biocapacity decreased, and the average trophic level of catches was 3.1, which implies that it has remained at average levels, resulting in a positive balance between biocapacity and ecological footprint. Therefore, under this approach, the fishing activity is sustainable along the coast of Jalisco.

Description: The impact of resources on social unrest is of increasing interest to political leaders, business and civil society. Recent events have highlighted that (lack of) access to critical resources, including food, energy and water, can, in certain circumstances, lead to violent demonstrations. In this paper, we assess a number of political fragility indices to see whether they are good indicators of propensity to food riots. We found that the most accurate is the Political Instability and Absence of Violence Indicator of the Worldwide Governance Indicators by the World Bank. We compute a likelihood of experiencing a food riot for each quartile of this index. We found that the self-sufficiency of food does not seem to affect the likelihood of the occurrence of food riots, but that the level of political stability of a country does have a role. In addition, we identify a monthly and annual threshold for the Food and Agriculture Organisation Food Price Index, above which food riots in fragile states are more likely to occur.

Description: During creep, magnesium alloys undergo microstructural changes due to temperature and stress. These alterations are associated with the evolution of the present phases at a microstructural level, creating different strain rates during primary and tertiary creep, and with the stability of the inter-metallic phase Mg17Al12 formed at these temperatures. In this paper, the results of creep testing of high-pressure die-cast AZ91 magnesium alloys are reported. During creep, continuous and discontinuous precipitates grow, which influences creep resistance. The creep mechanism that acts at these intermediate temperatures up to 150 °C is termed dislocation climbing. Finally, the influence of the type of precipitates on the creep behavior of alloys is determined by promoting the formation of continuous precipitates by a short heat treatment prior to creep testing.

Description: Despite the knowledge gained in recent years regarding the use of acoustic emissions (AEs) in ecologically friendly, natural fiber-reinforced composites (including certain composites with bio-sourced matrices), there is still a knowledge gap in the understanding of the difference in damage behavior between green and biocomposites. Thus, this article investigates the behavior of two comparable green and biocomposites with tests that better reflect real-life applications, i.e., load-unloading and creep testing, to determine the evolution of the damage process. Comparing the mechanical results with the AE, it can be concluded that the addition of a coupling agent (CA) markedly reduced the ratio of AE damage to mechanical damage. CA had an extremely beneficial effect on green composites because the Kaiser effect was dominant during cyclic testing. During the creep tests, the use of a CA also avoided the transition to new damaging phases in both composites. The long-term applications of PE green material must be chosen carefully because bio and green composites with similar properties exhibited different damage processes in tests such as cycling and creep that could not be previously understood using only monotonic testing.

Description: Materials, Vol. 11, Pages 1491: A New Prediction Method for the Ultimate Tensile Strength of Steel Alloys with Small Punch Test Materials doi: 10.3390/ma11091491 Authors: Jose Calaf Chica Pedro Miguel Bravo Díez Mónica Preciado Calzada The load–deflection curve acquired from the Small Punch Test (SPT) is used to obtain the mechanical properties of materials using different correlation methods. The scattering level of these regressions tends to be high when a wide set of materials is analyzed. In this study, a correlation method based on a specific slope of the SPT curve was proposed to reduce scattering. Assuming the Ramberg–Osgood hardening law, the dependence of the SPT curve slope on the yield strength and the hardening coefficient is demonstrated by numerical simulations (FEM). Considering that the ultimate tensile strength could be obtained from the hardening coefficient, a response surface of the ultimate tensile strength with the yield strength and SPT curve slope, along with its equation, is presented for steel alloys. A summary of steel mechanical properties, based on the Boiler and Pressure Vessel Code (BPVC) and limited to yield strengths lower than 1300 MPa, is shown to select a set of experimental tests (tensile tests and SPTs) for which the range is completely covered. This experimental analysis validates the previous FEM analyses and the validity of the proposed correlation method, which shows more accurate correlations compared to the current methods.

Description: The contents of Education for Sustainable Development should be included in teachers’ initial and advanced training programs. A sustainable consciousness is one of the main foundations for determining the key competences for sustainability. However, there are not many empirical studies that deal with consciousness from education. In this context, the e-portfolio appears as a tool that promotes reflection and critical thinking, which are key competences for consciousness development. This work intends to propose a categorization system to extract types of consciousness and identify the levels of consciousness of teachers in training. For this research work, which is of an eminently qualitative nature, we have selected 25 e-portfolios of students (teachers in pre-service training) in the last year of the School of Education at the University of Macerata (Italy). The qualitative methodological procedure that was followed enabled deducing three bases that shape the consciousness of teachers in training: thinking, representation of reality, and type of consciousness. We concluded that the attainment of a sustainable consciousness in teachers requires activating and developing higher levels of thinking, as well as a projective and macrostructural representation of reality.

Description: In this manuscript, the equilibrium problem for a flexoelectric one-dimensional composite material is studied. The two-scales asymptotic homogenization method is used to derive the homogenized formulation of this problem. The manuscript offers a step-by-step methodology to derive effective coefficients and to solve local problems. As an illustrative example, results reported in the literature for piezoelectric composites are obtained as a particular case of the formulation derived here. Finally, three flexoelectric/piezoelectric composites are studied to illustrate the influence of the flexoelectric property on the effective coefficients and the global behavior of the structure.