Estrategias didácticas para favorecer el aprendizaje en las carreras de Ingeniería utilizando tecnologías de información y comunicación (TICS)

En el proceso de formación de los estudiantes de carreras de ingeniería existe regularmente un índice considerable de reprobación y deserción. Se analizan los factores que inciden en esta problemática y se proponen distintas estrategias didácticas con TICs (Tecnologías para la Educación) para favorecer el proceso de enseñanza-aprendizaje en las materias de Física clásica. Se utilizó el software “Easy Java Simulations” (EJS) basado en applets para la creación de simulaciones discretas y facilitar un proceso de aprendizaje significativo de los conceptos matemáticos y físicos que constituyen la base de su carrera profesional. El uso de simuladores provocó en el estudiante su propia compresión acerca de los fenómenos y leyes físicas desarrollando una compresión de las relaciones entre conceptos físicos, variables y fenómenos

Educação CTS e articulação entre educação não-formal e formal com recurso a um courseware didáctico

Considerando recomendações da investigação em educação em ciências e a tendência global de promoção das TIC, está em desenvolvimento um estudo de natureza qualitativa cuja finalidade é a concepção, produção, implementação e avaliação de um courseware didáctico de cariz CTS que articule contextos formais e não-formais de educação. Este courseware abordará a eficiência energética e fontes energéticas renováveis e procurará incluir, particularmente para crianças dos 8 aos 12 anos, uma articulação entre actividades escolares e o espaço Jardim de Ciência da Universidade de Aveiro. A avaliação será realizada pela caracterização das concepções CTS, práticas didáctico-pedagógicas, e recurso a meios de educação não-formal por um grupo de professores. Algumas das actividades em desenvolvimento serão objecto de apresentação nesta comunicação

Evaluación química y sensorial del jamón serrano en el callejón de Huaylas

En el callejón de Huaylas se expenden jamones elaborados artesanalmente sin tomar en cuenta los criterios tecnológicos. En la etapa del curado seco utilizan sales de nitrato (salitre) en cantidades inadecuadas, como por ejemplo adición en cucharadas que no permiten una correcta dosificación de acuerdo a las normas estándares de calidad. El riesgo del uso de nitratos y nitritos es la formación de nitrosaminas, substancias que son agentes cancerígenos. La hipótesis que se planteó en el presente trabajo de investigación es si se realiza el análisis químico y sensorial del jamón serrano en el callejón de Huaylas, entonces se determinará su nivel de calidad del producto

Evidence of trauma in a ca. 1-million-year-old patella of Homo antecessor, Gran Dolina-Atapuerca (Spain)

We present the palaeopathological study of a left patella (ATD6-56) belonging to the Early Pleistocene species Homo antecessor (Atapuerca-Gran Dolina, Spain). The abnormal morphology observed in the inferior margin of the patella is an osseous overgrowth (osteophyte). Macroscopic and microscopic techniques, including microtomography and zoom stereomicroscope, were used to describe the lesion. Externally, the osteophyte has a smooth and porous texture; the boundary between the more radiolucent osteophyte and the normal bone can be identified in X-ray images. We suggest that the observed signs could be secondary to a local trauma. The lesion would have involved either the bone or related soft tissues of the left limb, possibly affecting the stability of the joint. Consequently, the individual's knee would have suffered an abnormal mechanical load that could have eventually triggered osteoarthritic changes. This is also supported by the lack of changes observed in the associated right patella (ATD6-22)

A Soft Sensor for Biomass in a Batch Process with Delayed Measurements

This paper presents a soft sensor to estimate the biomass concentration in a batch bioprocess used in production of δ-endotoxins of Bacillus thuringiensis, subject to delayed measurements. The soft sensor proposed is based on a cascade observer-predictor algorithm. The observer stage is based on a class of second order sliding mode algorithms, allowing a fixed time estimation of the biomass. Additionally, the prediction stage offsets the effect of the delay in measurements. Simulations show the feasibility of the proposed observer.Universidad Nacional de ColombiaCINVESTAV-IPNITESO, A.C

An Equivalent Control Based Observer for Biomass in a Batch Process

In this paper a sliding-mode observer for a batch bioprocess, the d-endotoxins production of bacillus thuringiensis (BT), is presented. The proposed observer is based on the equivalent control method and a class of second-order sliding mode operators. The use of these operators in the observer design allows the fixed-time convergence of the measured variables, while the unmeasured variables converge exponentially. This structure allows to estimate the biomass in the d-endotoxins production of BT, even, under noisy measurement conditions. Simulations show the feasibility of the proposed observer. Convergence proofs are also presented

Educação cts e articulação entre educação não-formal e formal com recurso a um courseware didáctico

Considerando recomendações da investigação em educação em ciências e a tendência global de promoção das TIC, está em desenvolvimento um estudo de natureza qualitativa cuja finalidade é a concepção, produção, implementação e avaliação de um courseware didáctico de cariz CTS que articule contextos formais e não-formais de educação. Este courseware abordará a eficiência energética e fontes energéticas renováveis e procurará incluir, particularmente para crianças dos 8 aos 12 anos, uma articulação entre actividades escolares e o espaço Jardim de Ciência da Universidade de Aveiro. A avaliação será realizada pela caracterização das concepções CTS, práticas didáctico-pedagógicas, e recurso a meios de educação não-formal por um grupo de professores. Algumas das actividades em desenvolvimento serão objecto de apresentação nesta comunicação

Two short mass-loss events that unveil the binary heart of Minkowski's Butterfly Nebula

Studying the appearance and properties of bipolar winds is critical to understand the stellar evolution from the AGB to the planetary nebula (PN) phase. Many uncertainties exist regarding the presence and role of binary stellar systems, mainly due to the deficit of conclusive observational evidences. We investigate the extended equatorial distribution around the early bipolar planetary nebula M 2-9 ("Minkowski's Butterfly Nebula") to gather new information on the mechanism of the axial ejections. Interferometric millimeter observations of molecular emission provide the most comprehensive view of the equatorial mass distribution and kinematics in early PNe. Here we present subarcsecond angular-resolution observations of the 12CO J=2-1 line and continuum emission with the Plateau de Bure interferometer. The data reveal two ring-shaped and eccentric structures at the equatorial basis of the two coaxial optical lobes. The two rings were formed during short mass-loss episodes (~ 40 yr), separated by ~ 500 yr. Their positional and dynamical imprints provide evidence of the presence of a binary stellar system at the center, which yields critical information on its orbital characteristics, including a mass estimate for the secondary of ~< 0.2 \ms. The presence of a stellar system with a modest-mass companion at the center of such an elongated bipolar PN strongly supports the binary-based models, because these are more easily able to explain the frequent axisymmetric ejections in PNe.Comment: 8 page

Anomalous Hall conductivity control in Mn3_3NiN antiperovskite by epitaxial strain along the kagome plane

Antiferromagnetic manganese-based nitride antiperovskites, such as Mn$_3$NiN, hold a triangular frustrated magnetic ordering over their kagome lattice formed by the Mn atoms along the (111)-plane. As such, frustration imposes a non-trivial interplay between the symmetric and asymmetric magnetic interactions, which can only reach equilibrium in a noncollinear magnetic configuration. Consequently, the associated electronic interactions and their possible tuning by external constraints, such as applied epitaxial strain, play a crucial role in defining the microscopic and macroscopic properties of such topological condensed matter systems. Thus, in the present work, we explored and explained the effect of the epitaxial strain imposed within the (111)-plane, in which the magnetic and crystallographic symmetry operations are kept fixed, and only the magnitude of the ionic and electronic interactions are tuned. We found a linear shifting in the energy of the band structure and a linear increase/decrease of the available states near the Fermi level with the applied strain. Concretely, the compression strain reduces the Mn-Mn distances in the (111) kagome plane but linearly increases the separation between the stacked kagome lattices and the available states near the Fermi level. Despite the linear controlling of the available states across the Fermi energy, the anomalous Hall conductivity shows a non-linear behavior where the $\sigma_{111}$ conductivity nearly vanishes for tensile strain. On the other hand, $\sigma_{111}$ fetches a maximum increase of 26\% about the unstrained structure for a compression value close to $-$1.5\%.This behavior found an explanation in the non-divergent Berry curvature within the kagome plane, which is increased for constraining but significantly reduced for expansion strain values..