ALBERT

Description: Background: The aim of the present study was to validate and develop the dimensions of the Personal Learning Environments (PLE) questionnaire with regards to the social integration of unaccompanied foreign minors (MENA), in addition to analyzing its psychometric properties. Methods: This study was conducted using an expert panel and exploratory techniques in a population of unaccompanied foreign minors (referred to hereon as MENA). The sample used for the validation was formed of 250 MENA aged between 13 and 17 years, with 206 (83.6%) being male and 41 (16.4%) being female. An expert panel was formed including 10 scholars of Education Sciences. The panel identified four dimensions, which were confirmed through exploratory factorial analysis conducted using the program called FACTOR Analysis (Lorenzo-Seva and Ferrando, 2006). Results: The results indicate that the PLE questionnaire provides reliable dimensions at the level α = 0.902. Examination of Pearson correlations identified significant values (p 〈 0.01) for almost all dimensions, with the highest value being produced for the association between the dimensions of communication and social interaction (CIS) and planning and management of learning (r = 0.641). Conclusions: From this study, it is concluded that the results of the study and the validation of the PLE in MENA populations through the four identified dimensions are valid and reliable for enabling multi-dimensional analyses to be carried out.

Description: Agriculture, Vol. 8, Pages 23: Territorial Governance and Social Innovation: The Cases of San Pedro Capula’s Artisanal Cheese and the Rice (Oryza Sativa) of Morelos, Mexico Agriculture doi: 10.3390/agriculture8020023 Authors: Jessica Tolentino Martínez María del Valle Rivera Over the last thirty-five years, Mexico has maintained a trade liberalization policy which has depressed food production and has reconstructed the structure of the agri-food sector; this has generated a higher food dependence and insecurity. In order to face this structural change, new organizational and socio-productive dynamics have emerged in communities, which take into consideration food diversity, heritage and cultural conditions of rural areas. In this paper, we use the theoretical approach of Localized Agrifood Systems (LAFS) and the operative concepts of governance and social innovation to analyze and understand the efforts that at the base of society are created to grant development of productive systems. Therefore, we present the results of an investigation based on the exploration of two LAFS cases; in these cases, different strategies to achieve development have been established: the elaboration of artisanal cheese in the state of Hidalgo, and the production of rice in the state of Morelos, Mexico. Research results show the importance of concepts such as Social Innovation (SI) and Governance within the framework of localized agri-food systems in rural studies, this, in order to identify the needs and potentials of family farming and producer’s groups inside the new contexts generated by globalization and market liberation process.

Description: Future agricultural development will be challenged by the impacts of climate change on water, which are expected to be particularly strong in southern European regions. Thus, exploring interrelations between agriculture and water under climate change is essential to frame informed policies that ensure sustainable water management while enhancing food production. Nevertheless, studies that address future agriculture development focus on climate-induced changes in crop productivity and often disregard the water dimension. In this research, we have conducted a sensitivity analysis of agricultural development to drivers of water use in Andalusia in 2050 based on outcomes from the CAPRI-Water model. The results from the analysis show that water cost is the most determinant factor in shaping agricultural land, offsetting the impact of the driver of water availability. In contrast, irrigation water use is driven not only by water cost but also by irrigation efficiency. The magnitude of the sensitivity to these drivers differs significantly across crops. Policies aimed at improving resource use efficiency can contribute to strengthening the resilience and adaptation capacity of future agricultural systems to climate change. To achieve this goal, the policies must consider crop sensitivity to irrigation costs and the potential rebound effect.

Description: Titanium is one of the most interesting materials in modern manufacturing thanks to its good mechanical properties and light weight. These features make it very attractive for use in the aeronautical and aerospace industries. Important alloys, such as Ti6Al4V, are extensively used. Nevertheless, titanium alloys present several problems in machining processes. Their machinability is poor, affected by low thermal conductivity, which generates very high cutting temperatures and thermal gradients in the cutting tool. Lubricants and cutting fluids have traditionally been used to solve this problem. However, this option is unsustainable as such lubricants represent a risk to the environment and to the health of the operator due to their different chemical components. Therefore, novel, sustainable and green lubrication techniques are necessary. Dry machining is the most sustainable option. Nevertheless, difficult-to-machine materials like titanium alloys cannot be machined under these conditions, leading to very high cutting temperatures and excessive tool wear. This study is intended to describe, analyse and review the non-traditional lubrication techniques developed in turning, drilling and milling processes since 2015, including minimum quantity of lubricant, cryogenic lubrication, minimum quantity of cooling lubrication or high-pressure coolant. The aim is to provide a general overview of the recent advances in each technique for the main machining processes.

Description: PbTe-based alloys have the best thermoelectric properties for intermediate temperature applications (500–900 K). We report on the preparation of pristine PbTe and two doped derivatives (Pb0.99Sb0.01Te and Ag0.05Sb0.05Pb0.9Te, so-called LAST18) by a fast arc-melting technique, yielding nanostructured polycrystalline pellets. XRD and neutron powder diffraction (NPD) data assessed the a slight Te deficiency for PbTe, also yielding trends on the displacement factors of the 4a and 4b sites of the cubic Fm-3m space group. Interestingly, SEM analysis shows the conspicuous formation of layers assembled as stackings of nano-sheets, with 20–30 nm thickness. TEM analysis shows intra-sheet nanostructuration on the 50 nm scale in the form of polycrystalline grains. Large numbers of grain boundaries are created by this nanostructuration and this may contribute to reduce the thermal conductivity to a record-low value of 1.6 Wm−1K−1 at room temperature. In LAST18, a positive Seebeck coefficient up to 600 μV K−1 at 450 K was observed, contributing further towards improving potential thermoelectric efficiency.

Description: Purpose: To analyze in vitro the mechanical behavior of five types of complete coverage crowns fabricated from different materials. Materials and methods: Seventy-five full coverage crowns were divided into five groups according to material: Group I, metal core with feldspathic ceramic covering (MC- control group); Group II, zirconia core with feldspathic ceramic covering (CZ); Group III, tetragonal monolithic zirconia (TMZ); Group IV, cubic monolithic zirconia (CMZ); Group V, high molecular weight polymethyl methacrylate (PMMAG) doped with graphene nanoparticles. All crowns underwent in vitro fatiguing by dynamic loading in wet conditions to simulate the masticatory forces to which prosthodontic materials are subject in the oral medium. Lastly, fracture resistance was evaluated by static compression testing. Results: The fracture resistance values obtained were as follows: Group MC, 2443.6 ± 238.6 N; Group CZ, 2095.4 ± 329.2 N; Group TMZ, 2494.6 ± 236.6 N; Group CMZ, 1523.6 ± 325.2 N; and Group PMMAG, 1708.9 ± 386.6 N. Group MC presented higher strength with statistically significant differences in comparison with Groups CZ (P = 0.002), CMZ (P 〈 0.001), and PMMAG (P 〈 0.001). Weibull distribution showed less probability of cumulative biomechanical failure in Groups MC and TMZ. Conclusions: Metal-ceramic and tetragonal zirconia showed high fracture resistance, while cubic zirconia and PMMA doped with graphene nanoparticles obtained lower values.