Geometric figures and mobile technology for numerical relations as a way to teach and learn in the XXI century

Les relacions numèriques actuals, com a part de les matemàtiques, utilitzen dibuixos, signes i codis, així com mètodes manuals que no han variat gaire durant centenars d'anys. Avui en dia, la irrupció dels dispositius mòbils ho desafia. Aquest nou enfocament capacita tant als estudiants com a persones amb discapacitat numèrica per aprendre relacions numèriques. S'obre un munt de noves possibilitats perquè la comprensió és més ràpida, la desconnexió cerebral és més curta .... La tecnologia MNT (Mobile Numbers Technology) amb figures geomètriques amplia la base de l'usuari.Postprint (author's final draft

Analysis of a problem based learning experience in a Fundamental Physics course

[ES] La universidad debe formar titulados con perfiles que respondan a una demanda, activa, más interdisciplinaria y flexible. Titulados que asuman la formación continua y su adaptabilidad a la demanda socio-cultural, en continuo cambio, como una herramienta necesaria para su propio desarrollo y el de su entorno. En este aspecto la universidad debe enseñar y educar. Debe enseñar a que el individuo redescubra su capacidad de aprendizaje y al disfrute de este don. La universidad ha de educar formando, al individuo en el aspecto de que no es el todo, sino que forma parte de un entramado en continuo cambio y que ha de saber adaptarse. Una nueva visión de la universidad se está gestionando basada en directrices y metodologías docentes diferentes respecto la visión clásica de Universidad. En este documento se detalla una experiencia de aplicación de la metodología de aprendizaje basado en problemas, APB, en la materia de Física II de la titulación de Diseño Industrial en el curso 2005-06, en una de las unidades temáticas (electrostática y corriente continua) así como el resultado académico de la evaluación y autoevaluación. También se hace constar una comparativa con el resultado académico obtenido en los años anteriores para la misma temática .[EN] The university must form professionals with profiles that respond to a social demand active, more interdisciplinary and flexible. It must form people who assume the continuous formation and consider its adaptability to the socio cultural demand, in continuous change, as a necessary tool for their own development and the one of its surroundings. In this aspect the university must teach and educate. It must teach to the students to rediscover his capacity of learning and to the benefit of this gift. The university has to educate forming to the students in the aspect that they are not the whole, but they form part of a framework in continuous change and that there is important to know how to perform the own adaptation. A new vision of the university is being managed based on directives and different educational methodologies respect the classic vision of University. In this document an experience of application of the methodology of problems based learning, APB, is detailed in the matter of Physics II of the degree of Industrial Design in course 2005-06. Specifically, it was applied in one of the course units (electrostatic and direct current). It is also analyzed the academic result of the evaluation and self evaluation. Also it is pointed out a comparative one with the obtained academic result in then previous years for the same thematic.Planella, J.; Escoda, ML.; Suñol, JJ. (2009). Análisis de una experiencia de aprendizaje basado en problemas en la asignatura de Fundamentos de física. REDU. Revista de Docencia Universitaria. 7(2):1-16. https://doi.org/10.4995/redu.2009.6239OJS11672Allen, D.E.; Duch, B.J.; Groh, S.E. (1997). "The power of problem-based learning teaching introductory science courses". En L.Wilkerson y W.H. Gijselacrs. Bringing problem based learning to higher education: Theory and practice (pp 43-52). San Francisco: Jossey-Bass.Aronson, E., Blaney, N., Stephan, C., Sikes, J., Snapp, M. (1978). The Jigsaw Classroom, Sage,Branda, L.A. (1997) Implementing problem based learning. J.Dent. Educ., 54 (pp 548-549)Cohen, E.G. (1994). Designing groupwork: Estrategies for heterogeneous classrooms. New York: Teachers College PressDoménech, F. (1999). La evaluación educativa Proceso Universitario/Aprendizaje Universitario. Universitas (pp133-175)Johnson, D.W., Johnson, R.T., Smith, K.A. (1991). "Cooperative learning: Increasing College Faculty Instructional Productivity", ASHE-ERIC Higher Education Report, 4, George Washintong UniversityMackinnon, M.M. (1996). "Core elements of student motivation in problem based learning". En M.Theall(Ed) Motivation from within: Approaches for encouraging faculty and students to excel (pp 49-58) San Francisco: Jossey-BassMarkham, T; Mergendoller, Larmer J. (2003). Project Based Learning Handbook. (2Ed). Buck Institute for EducationPedersen, S. (2003). Motivational orientation in a problem based learning environment. Journal of Interactive learning Research 14: (pp 51-77)Rhem, J. (1998). "Problem based learning. An introduction". Disponible en http://www.ntlf.com/Zabala, M.A (2001). Evaluación de los aprendizajes en la Universidad Didàctica Universitària. Madrid (pp 261-291

Ni-Mn-Sn-Cu Alloys after Thermal Cycling: Thermal and Magnetic Response

Heusler Ni-Mn-Sn-based alloys are good candidates for magnetic refrigeration. This application is based on cycling processes. In this work, thermal cycles (100) have been performed in three ribbons produced by melt-spinning to check the thermal stability and the magnetic response. After cycling, the temperatures were slowly shifted and the thermodynamic properties were reduced, the entropy changed at about 3–5%. Likewise, the thermomagnetic response remains similar. Thus, these candidates maintain enough thermal stability and magnetic response after cycling. Likewise, Cu addition shifts the structural transformation to higher temperatures, whereas the Curie temperature is always near 310 K. Regarding magnetic shape memory applications, the best candidate is the Ni49Mn36 Sn14Cu1 alloy.This study was funded by University of Girona PONT2020-01 and Spanish Mineco MAT2016-75967-P projects

La docència de la física: cap a un paradigma amb tecnologia mòbil

La docència de la física implica l'ús d'equacions i procediments matemàtics. Els mètodes docents actuals es basen en l'ús de la intel·ligència logica-matemàtica però la irrupció dels dispositius mòbils augura una nova forma d'educació basada en el context gràfic i els gestos de pantalla multitàctil. El seu ús és intuïtiu i l'aprenentatge ràpid i intuïtiu. En un sentit ampli, es tracta d'una tecnologia més propera als nadius digitals i que amplia la base d'usuarisPostprint (author's final draft

Microstructural and Magnetic Behavior of Nanocrystalline Fe-12Ni-16B-2Si Alloy Synthesis and Characterization

The nanocrystalline Fe70Ni12B16Si2 (at.%) alloy was prepared by mechanical alloying (MA) of elemental powders in a high-energy planetary ball mill. Phase evolution, microstructure, thermal behavior and magnetic properties were investigated. It was found that a body-centered cubic structured solid solution started to form after 25 h milling and a faced-centered cubic structure solid solution started to form after 50 h of milling; its amount increased gradually with increasing milling time. The BCC and the FCC phases coexisted after 150 h of milling, with a refined microstructure of 13 nm and a 10 nm crystallite size. The as-milled powder was annealed at 450 °C and 650 °C and then investigated by vibrating sample magnetometry (VSM). It was shown that the semi-hard magnetic properties are affected by the phase transformation on annealing. The saturation magnetization decreases after annealing at 450 °C, whereas annealing at 650 °C improves the magnetic properties of 150 h milled powders through the reduction of coercivity from 109 Oe to 70 Oe and the increase in saturation magnetization

Martensitic Transformation, Thermal Analysis and Magnetocaloric Properties of Ni-Mn-Sn-Pd Alloys

Martensitic transition and magnetic response of Ni50−x Pdx,y Mn36 Sn14−y (x = 0, 1, 2 and y = 0, 1) Heusler alloys were analysed. The crystalline structure of each composition was solved by X-ray diffraction pattern fitting. For x = 1 and 2, the L21 austenite structure is formed and, for y = 1, the crystallographic phase is a modulated martensitic structure. From differential scanning calorimetry scans, we determine characteristic transformation temperatures and the entropy/enthalpy changes. The temperatures of the structural transformation increase with the addition of Pd to replace Ni or Sn, whereas the austenitic Curie temperature remains almost unvarying. In addition, the magneto-structural transition, investigated by magnetic measurements, is adjusted by suitable Pd doping in the alloys. The peak value of the magnetic entropy changes reached 4.5 J/(kg K) for Ni50Mn36Sn13Pd1 (external field: 50 kOe).This research was funded by MINECO grant MAT2016-75967-P and UdG grant PONT2020/01

Tailoring of magnetocaloric effect in Ni45.5Mn43.0In11.5 metamagnetic shape memory alloy

We investigate the direct and inverse magnetocaloric effect in Ni45.5Mn43.0In11.5 Heusler alloy ribbons comparing the results obtained for the as-quenched sample with the ones after different annealing procedures. An enhancement and shift of the entropy maximum to near room temperature is observed in all annealed samples. A remarkable magnetocaloric effect is observed in samples with short-time treatment (10 minutes) and at the lowest annealing temperature. We show that the suppressing of uncompensated martensitic transition and thermal hysteresis are both influenced by the heat treatment. Also, an improvement on Curie’s temperature is observed and, at low magnetic field, it has been risen up to 310 K. Our results demonstrate that the martensitic transformation is highly sensitive to the applied magnetic field and also to the annealing treatment, which means that the magnetocaloric effect can be tuned showing different behaviors for each sample.Authors are thankful to Spanish MICINN for financial support: MAT2009-13108-C02-01-02 and MAT2010-20798-C05-04. L. Gonzalez also thanks MICINN for a FPI Grant and J. García FICYT for a “Severo Ochoa” Grant

Mechanical Alloying: Processing and Materials

Mechanical alloying is a technique involving the production of alloys and compounds, which permits the development of metastable materials (with amorphous or nanocrystalline microstructure) or the obtention of solid solutions with extended solubility [...

All-<i>d</i>-Metal Heusler Alloys: A Review

Heusler alloy research has increased considerably in recent years. This is mostly due to their strong desire to develop future smart device applications. However, many limiting variables remain for researchers to overcome in order to enhance their functional properties. The poor mechanical properties of these alloys restrict their use as solid-state cooling materials in magnetic refrigeration devices. A promising strategy, resulting in novel compounds with better mechanical properties and substantial magnetocaloric effects, is favoring the d–d hybridization with transition-metal elements to replace p–d hybridization. The term given to these materials is “all-d-metal”. In light of recent experimental results of the magnetocaloric effect and the increased mechanical characteristics in these alloys (with complex crystallographic behavior due to off-stoichiometry and disorder), a review of this advanced functional behavior is offered. Moreover, the impact of the substitution of transition metal for the p-group to increase mechanical ductility and considerable magnetocaloric effects has also been addressed. These Heusler alloys are a potential new class of materials for technological applications because of their optimum functional behavior. Finally, we highlighted the potential challenges and unsolved issues in order to guide future studies on this topic