Repositorio Institucional UCSC (Univ. Católica de la Santísima Concepción)
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Desempenho académico e emoções de realização dos alunos do ensino básico numa intervenção com tecnologias imersivas na sala de aula de matemática
Get PDFLa evidencia sobre el efecto de tecnologías inmersivas en el aprendizaje es contradictoria, pues a menudo se presta mayor atención a la tecnología que a la pedagogía. La investigación buscó determinar el efecto de la realidad aumentada y la realidad virtual en el rendimiento académico de estudiantes de cuarto grado en educación matemática, así como describir las emociones de logro en la intervención pedagógica. El diseño antes y después se realizó con un grupo de 35 estudiantes, 21 niños y 14 niñas, con una edad promedio de 9 años, pertenecientes a una escuela de Chile. La intervención consistió en tres sesiones de 90 minutos cada una, donde el estudiantado pudo interactuar con tecnologías para fortalecer sus conceptos geométricos. Además, se administraron pruebas de contenido antes y después para la evaluación del aprendizaje, y un cuestionario de emociones durante la intervención. Los resultados revelaron un efecto significativo en el rendimiento académico, demostrando un tamaño del efecto grande (d = .79). Los hallazgos indican la ausencia de diferencias significativas en el desempeño entre niños y niñas. Además, se identificaron emociones positivas en las actividades. La investigación aboga por la priorización de objetivos y de resultados de aprendizaje por encima de la contribución tecnológica
Systematic review on the integration of immersive technologies to improve learning in primary education
No full textImmersive technologies such as augmented reality and virtual reality have attracted a great deal of interest in educational research; they have the potential to enhance learning by providing interactive, realistic, and safe experiences without the constraints of time and space. This study is based on a systematic review of the literature following the guidelines of the PRISMA statement. The scientific production related to the integration of immersive technologies in learning processes in primary education was examined. The Web of Science, Scopus and ERIC databases were searched, considering the period from 2018 to 2023. The sample consisted of 64 studies that met the established inclusion criteria. The results showed a higher production of studies in Asia, a lack of theoretical support for the integration of immersive technologies, and a greater focus on science education. In conclusion, it is highlighted that studies focus on the effect of immersive technologies on academic achievement without sufficiently addressing the cognitive and affective experience of students. The study presents a classification framework grounded in the stimulus-organism-response model, offering recommendations for future research and practical implications for educators, educational policy makers, and digital content designers
The Atacama Cosmology Telescope: Quantifying atmospheric emission above Cerro Toco
No full textAt frequencies below 1 Hz, fluctuations in atmospheric emission in the Chajnantor region in northern Chile are the primary source of interference for bolometric millimeter-wave observations. This paper focuses on characterizing the statistics of these fluctuations using measurements from the Atacama Cosmology Telescope (ACT) and the Atacama Pathfinder Experiment (APEX) water vapor radiometer. We show that the total precipitable water vapor (PWV) is not in general an accurate estimator of the level of fluctuations in millimeter-wave atmospheric emission. We also show that the microwave frequency spectrum of atmospheric fluctuations is in good agreement with predictions by the am code for frequency bands above 90 GHz. We introduce a new method for separating atmospheric and systematic fluctuations, allowing us to fit a robust atmospheric flat field, as well as to study in the atmosphere in greater detail than previous works. We present a direct measurement of the temporal outer scale of turbulence of 0 ≈50 s corresponding to a spatial scale of 0 ≈500 m. Lastly, we show the variance of fluctuations in ACT’s mm-wave bands correlate with the variance of fluctuations in PWV measured by APEX, even though the observatories are 6 km apart and observe different lines of sight
Marine resource projects for rural economic development policies in Chile: marine user rights and disruption costs
No full textGovernments offer resource user rights, such as individual and collective agricultural land rights, fishing quotas, and territorial user rights in marine activities, to induce economic development and efficient resource use. Yet, user rights and improved incomes do not always lead to project uptake, as in rural-rural migration. Marine user rights may differ from land tenure rights, especially when rights are individual or collective. We explore household survey data from Chile about participation in projects linking marine resource activities with user rights across payoff levels and commute/relocation ‘disruption’ costs. Households are more likely to participate in projects with low disruption costs and high incomes, yet many households reject lucrative projects. The household's existing user rights and the project's activity–rights pairs affect project participation levels, with differences across collective and individually-held rights. These results inform policy aimed at increasing incomes and resource use efficiency through marine resource projects with user rights
Effectiveness of a load-level isolation system (LLIS) for industrial steel storage racks: Experimental validation on a shake table
No full textThis article presents the validation of a load-level isolation system designed for seismic protection and vibration control of industrial storage racks. This system exhibits the necessary versatility to protect the structure against different seismic intensities. The objective is to verify the effectiveness of the studied load-level isolation system in reducing the structural response and improving the seismic performance of the industrial racking, validating it with experimental tests. This was carried out on a shaking table with a total of 12 two-level rack tested at full scale, with 6 in conventional use conditions and 6 with the load-level isolation system. The 2010 earthquake in El Maule, Chile, was used as a forcing, scaled in the frequency domain to adjust its response spectrum with the design spectrum of NCh2369Of.2023. In the tests, the amount and distribution of the mass were varied, repeating the test for the design earthquake scaled to 10 %, 20 %, … 100 %. The results indicated that the implementation of the isolation system achieved a reduction of between 40 % and 81 % in floor deformations, and between 49 % and 63 % in the base shear, being able to resist up to at least 120 of the design earthquakes considered. The isolation system proved effective in protecting the structural integrity of the storage rack from low, medium, and high-intensity earthquakes
Primal-mixed finite element methods for the coupled Biot and Poisson–Nernst–Planck equations
Get PDFWe propose mixed finite element methods for the coupled Biot poroelasticity and Poisson–Nernst–Planck equations (modeling ion transport in deformable porous media). For the poroelasticity, we consider a primal-mixed, four-field formulation in terms of the solid displacement, the fluid pressure, the Darcy flux, and the total pressure. In turn, the Poisson–Nernst–Planck equations are formulated in terms of the electrostatic potential, the electric field, the ionized particle concentrations, their gradients, and the total ionic fluxes. The weak formulation, posed in Banach spaces, exhibits the structure of a perturbed block-diagonal operator consisting of perturbed and generalized saddle-point problems for the Biot equations, a generalized saddle-point system for the Poisson equations, and a perturbed twofold saddle-point problem for the Nernst–Planck equations. One of the main novelties here is the well-posedness analysis, hinging on the Banach fixed-point theorem along with small data assumptions, the Babuška–Brezzi theory in Banach spaces, and a slight variant of recent abstract results for perturbed saddle-point problems, again in Banach spaces. The associated Galerkin scheme is addressed similarly, employing the Banach fixed-point theorem to yield discrete well-posedness. A priori error estimates are derived, and simple numerical examples validate the theoretical error bounds, and illustrate the performance of the proposed schemes
Poly(lactide) and Ni nanoparticles supported thermally reduced graphene oxide nanoarchitecture for magnetic stimuli‐responsive material
No full textIn recent years, biodegradable plastics have gained significant attention as a strategy to reduce environmental contamination. However, achieving uniform dispersion of magnetic nanoparticles (MNPs) in polymers remains challenging due to magnetic aggregation. Core-shell encapsulation has emerged as an effective method to address this issue. In this study, nickel (Ni) nanoparticles (NPs) were supported on thermally reduced graphene oxide (TrGO), reduced at two distinct temperatures (600 and 1000°C), and used as nano-fillers to fabricate PLA nanocomposites. The mechanical, thermal, and magnetic properties of these composites were systematically investigated. X-ray diffraction (XRD) analysis displayed characteristic peaks for both graphene and Ni, with an estimated Ni NP size of 3.59 nm. Raman spectroscopy confirmed the D and G bands of graphene, along with distinct peaks of Ni. Surface area and elemental analyses indicated an increase in surface area and carbon content with thermal reduction, followed by a predictable decrease after supporting Ni NPs. Atomic absorption spectroscopy revealed that 8–12 wt.% of MNPs were successfully loaded onto the TrGO surface. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the polymer's chemical structure remained unchanged after nanoparticle incorporation. Uniform dispersion of the filler was observed through fracture interface scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Thermogravimetric analysis (TGA) showed a slight improvement in the initial degradation temperature of the PLA nanocomposites upon NP addition, although the final thermal stability was lower compared to neat PLA. Differential scanning calorimetry (DSC) showed a small increase in crystallinity, while the melting temperature remained unchanged. The addition of the filler led to a slight improvement in the elastic modulus. The hydrophilic nature of the nanocomposites was confirmed by water contact angle measurements. Notably, the incorporation of TrGO-Ni nanoparticles converted the original diamagnetic PLA matrix into a ferromagnetic material
Development and validation of an instrument to assess the perception of competencies and level of preparedness in telehealth
No full textIntroducción Se requiere contar con un instrumento validado que evalúe percepción de competencias y el nivel de preparación que poseen los profesionales y técnicos que realizan atenciones en salud de manera telemática en Chile.
Objetivo Desarrollar y evaluar la confiabilidad y validez de un instrumento diseñado para medir percepción de competencias y el nivel de preparación en telesalud.
Métodos Se diseñó un instrumento sobre competencias y nivel de preparación en telesalud, obteniendo validez de contenido mediante juicio experto. Luego, se aplicó el instrumento durante el año 2023 a un total de 83 profesionales y técnicos de la salud con experiencia en telesalud. Para determinar validez de constructo, se realizó análisis factorial exploratorio, extrayendo los factores mediante ejes principales. Además, se estimó el número de factores combinando análisis paralelo de Horn y gráfico de sedimentación. La rotación se realizó mediante el método Oblimin. Para estimar fiabilidad, se calculó el estadístico α de Cronbach.
Resultados El análisis factorial permitió identificar los ítems que cargaban sobre 0,6, generando así una escala final de dos factores, con un total de 30 ítems. Este modelo factorial explicó 75,5% de la varianza total. El primer factor reúne los ítems que evalúan percepción de competencias en telesalud. El segundo, evalúa percepción del nivel de preparación en telesalud. Ambos factores presentan indicadores de fiabilidad adecuados, con α de Cronbach de 0,98 y 0,97 respectivamente, mostrando correlaciones consideradas adecuadas.
Conclusiones El instrumento cuenta con indicadores psicométricos adecuados, aun considerando el tamaño muestral, para medir la percepción de competencias y nivel de preparación en telesalud en profesionales y técnicos de la salud de la Región del Biobío. Ambos factores que componen el instrumento permiten identificar necesidades de capacitación y formación. Se sugiere ampliar validación a muestras de otras regiones y aumentar la diversidad de disciplinas clínicas