88 research outputs found

    Ethnographic "experimental collaborations" as practitioner methodology

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    In this paper we discuss emergent cross-cutting themes across a series of educational intervention projects in which practitioners-in-training adopted and adapted in their proposals and work design the logic of ethnographic experimental collaboration (XCOL) and participatory action research (PAR) (Clark, 2010; Estalella & Sánchez-Criado, 2018) perspectives. We were involved in three interventions developed in Madrid (Spain) across formal and informal learning contexts as part of the internship/practicum of future educational psychologists. Our work was designed in response to the identified needs and demands of the internship sites. Yet, as educational interventions, they were explicitly conceptualized and implemented in ways that depart substantially from the common expectations of process-product educational intervention and dominant ways, at least in Spain, of constructing educational accountability (cf. Berliner, 1989; Gage & Needels, 1989). We unpack four themes relevant across the three projects, which emerged from our joint discussions of the three interventions: (a) how "outcomes/results" are reconstructed in XCOL/PAR educational interventions, (b) the transformations in our emergent professional identities, (c) the place of different materialities and expressive media in the work we planned (d) how space-time constraints were construed in our unfolding projects

    Thermal conductivity and viscosity measurements of ethylene glycol-based Al2O3 nanofluids

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    The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles in ethylene glycol have been analyzed at several concentrations up to 25% in mass fraction. The thermal conductivity and viscosity were experimentally determined at temperatures ranging from 283.15 K to 323.15 K using an apparatus based on the hot-wire method and a rotational viscometer, respectively. It has been found that both thermal conductivity and viscosity increase with the concentration of nanoparticles, whereas when the temperature increases the viscosity diminishes and the thermal conductivity rises. Measured enhancements on thermal conductivity (up to 19%) compare well with literature values when available. New viscosity experimental data yield values more than twice larger than the base fluid. The influence of particle size on viscosity has been also studied, finding large differences that must be taken into account for any practical application. These experimental results were compared with some theoretical models, as those of Maxwell-Hamilton and Crosser for thermal conductivity and Krieger and Dougherty for viscosity

    Drivers of winegrowers' decision on land use abandonment based on exploratory spatial data analysis and multilevel models

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    The frequency of producers opting to abandon agricultural land has become increasingly, highlighting the significance of this phenomenon due to its environmental, landscape, and socio-economic impacts. The decisions of producers to abandon or maintain/improve their farms depend on individual and contextual factors. The aims of this research are twofold. Firstly, to evaluate the influence of the neighbours on the winegrowers' decisions, using spatial analysis. Secondly, to clarify the specific importance of each of the individual and contextual drivers in farmers' decisions to improve their farms, to keep them unchanged or to abandon them, using multilevel models. The results obtained for the case study of vineyards in Spain, reveal a strong agglomeration phenomenon in farmers' decisions indicating that producers make land use decisions influenced by what their neighbours do. A multilevel analysis identifies that individual factors are determinant and that the influence of contextual factors is conditioned by the innovation process at farm level. Individual drivers, such as size, innovation, Protected Designations of Origin and irrigation influence vineyard area, with irrigation having the greatest overall influence, and is expected to be decisive in climate change projections. The Protected Designations of Origin are driving forces that dynamize the territory and achieve productive concentrations, encouraging winegrowers to replant, but they are not enough to halt abandonment. The elements that slow down the abandonment of plots are irrigation and the combination of innovation and context variables, mainly the combination of modernised plots in the municipalities with trading options.Ministry of Science and Innovation, Spain, European Regional Development Fund, European Commission. Project “Strengthening innovation policy in the agri-food sector” (RTI2018-093791-B-C22). And the authors acknowledge the support received from the Universitat Politècnica de València through the research project “Young people and social and organizational innovation in areas with demographic risk” integrated in the research line "Socio-economic analysis of innovation in sustainable agri-food systems (SAS)" and the Universidad Pública de Navarra through the research project 2022 PRO-UPNA 11504

    Rheological non-Newtonian behaviour of ethylene glycol-based Fe2O3 nanofluids

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    The rheological behaviour of ethylene glycol-based nanofluids containing hexagonal scalenohedral-shaped α-Fe2O3 (hematite) nanoparticles at 303.15 K and particle weight concentrations up to 25% has been carried out using a cone-plate Physica MCR rheometer. The tests performed show that the studied nanofluids present non-Newtonian shear-thinning behaviour. In addition, the viscosity at a given shear rate is time dependent, i.e. the fluid is thixotropic. Finally, using strain sweep and frequency sweep tests, the storage modulus G', loss modulus G″ and damping factor were determined as a function of the frequency showing viscoelastic behaviour for all samples

    Evolution of Gaseous and Particulate Pollutants in the Air: What Changed after Five Lockdown Weeks at a Southwest Atlantic European Region (Northwest of Spain) Due to the SARS-CoV-2 Pandemic?

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    [Abstract] Due to the exponential growth of the SARS-CoV-2 pandemic in Spain (2020), the Spanish Government adopted lockdown measures as mitigating strategies to reduce the spread of the pandemic from 14 March. In this paper, we report the results of the change in air quality at two Atlantic Coastal European cities (Northwest Spain) during five lockdown weeks. The temporal evolution of gaseous (nitrogen oxides, comprising NOₓ, NO, and NO₂; sulfur dioxide, SO₂; carbon monoxide, CO; and ozone, O₃) and particulate matter (PM₁₀; PM₂․₅; and equivalent black carbon, eBC) pollutants were recorded before (7 February to 13 March 2020) and during the first five lockdown weeks (14 March to 20 April 2020) at seven air quality monitoring stations (urban background, traffic, and industrial) in the cities of A Coruña and Vigo. The influences of the backward trajectories and meteorological parameters on air pollutant concentrations were considered during the studied period. The temporal trends indicate that the concentrations of almost all species steadily decreased during the lockdown period with statistical significance, with respect to the pre-lockdown period. In this context, great reductions were observed for pollutants related mainly to fossil fuel combustion, road traffic, and shipping emissions (−38 to −78% for NO, −22 to −69% for NO₂, −26 to −75% for NOₓ, −3 to −77% for SO₂, −21% for CO, −25 to −49% for PM₁₀, −10 to −38% for PM₂․₅, and −29 to −51% for eBC). Conversely, O₃ concentrations increased from +5 to +16%. Finally, pollutant concentration data for 14 March to 20 April of 2020 were compared with those of the previous two years. The results show that the overall air pollutants levels were higher during 2018–2019 than during the lockdown period.This work was supported by Ministerio de Ciencia, Innovación y Universidades (MCIU), Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) (Programa Estatal de I+D+i Orientada a los Retos de la Sociedad, ref: RTI 2018-101116-B-I00), Xunta de Galicia (Programa de Consolidación y Estructuración de Unidades de Investigación Competitivas ref: ED431C 2017/28-2017-2020) and FEDER-MINECO (UNLC15-DE-3097, financed together (80/20%) with Xunta de Galicia). Joel Sánchez-Piñero acknowledges the Xunta de Galicia and the European Union (European Social Fund-ESF) for a predoctoral grant (ED481A-2018/164). María Fernández-Amado acknowledges the Ministerio de Ciencia, Innovación y Universidades (PTA2017-13607-I)

    Clinical evaluation of two consanguineous families with homozygous mutations in BEST1

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    Purpose: To describe the clinical and genetic findings in two consanguineous families with Best vitelliform macular dystrophy (BVMD) and homozygous mutations in the bestrophin-1 (BEST1) gene. Methods: Ophthalmologic examination was performed in eight members of two families originating from Spain and Denmark. Mutation screening was performed using the Vitelliform Macular Dystrophy mutation array from Asper Biotech, and by the directed genomic sequencing of BEST1. Results: Two homozygous mutations were detected in these families. Mutation c.936C>A (p.Asp312Glu) has been reported previously in a Danish family; here, we describe four additional individuals in this family demonstrating findings compatible with a severe dominant BVMD, albeit with reduced penetrance in heterozygotes. In the Spanish family, a novel homozygous missense mutation in exon 4, c. 388 C>A (p.Arg130Ser), was identified in the siblings. Homozygous siblings demonstrated evidence of multifocal vitelliform retinopathy, whereas heterozygous family members presented findings ranging from isolated reduction of the electrooculogram Arden ratio to normal values on all clinical parameters. Conclusions: As demonstrated in these consanguineous families, a great clinical variability is associated with homozygous mutations in BEST1, ranging from severe dominant BVMD with reduced penetrance in heterozygotes to autosomal recessive bestrophinopathy

    Children Cautious Strategy and Variable Maturation Time Window for Responding in a Visual Search Task

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    Present study evaluates the changes and developmental trajectories of the attentional serial visual search and pre-attentional parallel search (pop-out) in situations in which a fast response is required. The hypothesis of present study are 1) that pre-attentional selection mechanisms develop before than serial attentional processes; 2) in the most difficult tasks, children prefer to adopt a non-responding strategy to an impulsive response patters; and 3) in speeded difficult discrimination tasks young children arrives to the criteria of correct performance in a broad temporal window. The results showed an inverse relationship between the age and the RTs and the different type of errors. For the present set of stimuli which produces an overcrowded scene and required a fast response, the behavioural trend of normal children is to the non-response pattern rather than to impulsive incorrect responses pattern. It can be suggested that young normal children present a broad temporal window to obtain the perceptual, motor and/or cognitive skills needed for responding adequately in a fast speeded discrimination task.Ministerio de Economía y Competitividad PSI2010- 1752

    Aggregation and phase equilibria of fluorinated ionic liquids

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    Grant SFRH/BD/100563/2014. IF/00190/2014 . IF/00210/2014. PTDC/EQU-EQU/29737/2017. PTDC/QEQ-FTT/3289/2014. IF/00210/2014/CP1244/CT0003. UID/QUI/50006/2019. POCI-01-0145-FEDER - 007265.In this work a specific family of ionic liquids, denominated fluorinated ionic liquids, with fluorine tags equal or longer than four carbon atoms, are fully characterized in order to understand their solubility and self-aggregation in aqueous solutions. The numerous combinations between cations and anions make these compounds a feasible option for the replacement of traditional and toxic surfactants used in the industrial and biomedical field. In this work, the increment of both hydrogenated and fluorinated side chain lengths, the influence of the cation headgroup (imidazolium and cholinium)as well as the difference between perfluorobutanesulfonate and perfluoropentanoate anions were studied. The liquid-liquid phase equilibria of fluorinated ionic liquids based on the perfluorobutanesulfonate anion with water were carried out. The self-aggregation behaviour of the different fluorinated ionic liquids in aqueous solutions was also determined using conductimetric titration, surface tension measurements and transmission electron microscopy. Several thermodynamic and surface parameters were obtained and used to discuss the aggregation process. These novel characterized fluorinated ionic liquids demonstrate an improved surface activity and aggregation behaviour, driven essentially by the increment of both hydrogenated and fluorinated chain lengths.authorsversionpublishe
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