Aprendizaje basado en proyectos: aplicación a la asignatura “Proyecto de Embarcaciones Rápidas y a Vela”

En este artículo se presenta la metodología de aprendizaje aplicada a la asignatura “Proyecto de Embarcaciones Rápidas y a Vela”, optativa del grado de Arquitectura Naval de la UPM. Proponemos un enfoque amplio basado en proyectos (PBL), con tres objetivos: que los alumnos realicen un ante-proyecto de embarcación rápida o a vela; que conecten con la realidad industrial del sector; y, por último, estimular su curiosidad y motivación hacia el contenido del curso. La asignatura se divide en dos bloques temáticos y tres módulos de trabajo, dos teóricos y uno práctico. Para evaluar el cumplimento de los objetivos propuestos se ha realizado una encuesta a los alumnos y se analizan algunos de los proyectos entregados por ellos. El artículo se cierra con conclusiones y propuestas de trabajo futuro

Characterizing a Mini Gamma Detector

There are several types of gamma radiation detectors, which have different characteristics depending on its use. We designed and instrumented a gamma detector for low energies of a small and portable size to obtain spectrum from radioactive sources and from that analyze each spectrum. This instrument basically consists of a scintillator crystal coupled to a SiPM this in turn coupled to a PCB card designed with capacitors and resistors for a better signal, a voltage source of 29 volts. For signal acquisition the system must be connected to an oscilloscope this in turn is controlled by a script developed in Python. For the calibration radioactive isotopes with the same dimensions were used, caesium-137 (Cs-137), cobalto-60 (Co-60), sodium-22 (Na-22) and manganese-54 (Mn-54) as gamma ray emission

Proposal of a Novel Setup for Linac Monitoring Using a Specifically Designed Plastic Scintillator and a Spectrophotometer

In this work we report the design, implementation and results of an alternative monitoring system for a linear accelerator (LINAC) used in medical therapy. The system proposed consist in aslab of scintillator plastic with awavelength shifter fiberoptically coupled to collect the light generated,and a Spectrophotometer Ocean Optics USB4000 as analyzer. The control was made with two computers, one into the therapy room and another, using a VNC (Virtual Network Computer) and Ethernet wire, outside of the room in order to avoid radiation exposure. The LINAC dose range covered was 1, 2, 3, 4, 5, 10, 20, 30 and 40 Monitor Units (MU) with 6 and 18 MeV energy photons. The spectrum obtained was compared with the measures of the LINAC ionization camera used to calibrate it. The results obtained allowus to propose this device as an alternative method to monitor the LINAC performance

Potenciar la experiencia y habilidades frente a problemas prácticos en las clases de laboratorio de “Flotabilidad y Estabilidad”

En este trabajo se presentan las medidas adoptadas en las prácticas de la asignatura “Flotabilidad y Estabilidad”, del grado de “Arquitectura Naval” de la UPM, para potenciar la capacidad de los alumnos de enfrentarse a problemas prácticos y para entender la casuística que ellos involucran (necesidad de planificación, manejo de herramientas, etc.). En concreto, se describen: a) Una actividad complementaria, introducida en el curso 2019/2020, que involucra la realización de un experimento con un barco real; b) La adaptación de las prácticas a formato no presencial en el curso 2020/2021. Este cambio de formato, consecuencia de la situación de pandemia, tiene en principio un efecto negativo en cuanto al objetivo que se persigue. Para tratar de minimizarlo, se introdujo un nuevo concepto de práctica en la que los alumnos realizaron un experimento casero, devolviendo así el aspecto práctico a la actividad, a pesar de la no presencialidad. En este artículo se evalúa la efectividad de las medidas implementadas en cuanto al cumplimento del objetivo de mejorar la capacidad de los alumnos de enfrentar problemas prácticos, así como de otros objetivos que se buscan con las prácticas. El artículo se cierra con conclusiones y propuestas de trabajo futuro

Validation of active forest fires detected by MSG-SEVIRI by means of MODIS hot spots and AWiFS images.

The detection of forest fires and the determination of their parameters have been usually carried out by polar-orbit sensors: AVHRR, (A)ATSR, BIRD and MODIS mainly. However, their time resolution prevents them from operating in real time. In contrast, the new geostationary sensors have very appropriate capacities for the observation of the Earth and monitoring of forest fires, as is being proved. GOES, MSG and MTSAT are already operative and they have led the international community to think that the global observation network in real time may become a reality. The implementation of this network is the aim of the Global Observations of Forest Cover and Land Cover Dynamics (GOFC/GOLD) FIRE Mapping and Monitoring program, focused internationally on taking decisions concerning the research of the Global Change. In this paper, the operation in real time by the MSG-SEVIRI sensor over the Iberian Peninsula is studied. On the other hand, the reliability of validation results by means of polar sensors, with better spatial resolution, is difficult to analyze due to errors caused by confused location of fires. This paper tries to find the most appropriate spatial scale to carry out comparison between Terra/Aqua-MODIS and Resourcesat1-AWiFS image

Study of secondary muons detected within the tunnels of the Cholula pyramid

The pyramid of Cholula was built at the beginning of 100 B.C. and during of period of 500 years it was finished, had several new constructions, based on the previous constructions. The primarily material of construction is the adobe. Early in 1931 archaeological excavations began with the intention of exploring the interior of the pyramid, excavations were stopped in 1971, and to date no further excavations have been carried out. This work shows the first measurements of muons, particles that are very penetrating, these are generated by primary cosmic rays that was incoming in the atmosphere and these generates a rain of secondary particles, among them the muons. To measure this kind of particles was implemented a detector system, it is formed by a scintillator plastic coupled to a tube photomultiplier; the signals were acquired by mean of an oscilloscope. The detector was collocated near of the center of the pyramid; the location belongs to the maxima concentration in mass over the detector. Graphs of the charge distribution, maximum amplitude and characteristic rise times of the generated pulses in a plastic scintillator are shown, this is scintillator was synthesized in the materials laboratory of the FCFM-BUAP. In addition the optical characterization of the same was realized

Optical studies of gap, hopping energies and the Anderson-Hubbard parameter in the zigzag-chain compound SrCuO2

We have investigated the electronic structure of the zigzag ladder (chain) compound SrCuO2 combining polarized optical absorption, reflection, photoreflectance and pseudo-dielectric function measurements with the model calculations. These measurements yield an energy gap of 1.42 eV (1.77 eV) at 300 K along (perpendicular) to the Cu-O chains. We have found that the lowest energy gap, the correlation gap, is temperature independent. The electronic structure of this oxide is calculated using both the local-spin-density-approximation with gradient correction method, and the tight-binding theory for the correlated electrons. The calculated density of electronic states for non-correlated and correlated electrons shows quasi-one-dimensional character. The correlation gap values of 1.42 eV (indirect transition) and 1.88 eV (direct transition) have been calculated with the electron hopping parameters t = 0.30 eV (along a chain), t_yz = 0.12 eV (between chains) and the Anderson-Hubbard repulsion on copper sites U= 2.0 eV. We concluded that SrCuO_2 belongs to the correlated-gap insulators.Comment: 24 pages, 8 figures, to be published in Phys.Rev.

Investigation of Different Iontophoretic Currents Profiles for Short-Term Applications in Cosmetics

[EN] This study aimed at investigating the effect of electrical current profile upon the iontophoretic transport of (i) ascorbic acid (AA) and (ii) ellagic acid (EA), into porcine skin in vitro, and the impact of the physicochemical properties of both actives on their mechanism of transport when formulated in cosmetic compositions. The experiments were performed using a proprietary iontophoretic device containing a roller to apply the formulation. Three current profiles were tested: (i) galvanic direct current (DC), (ii) square unipolar pulse current (SPC), and (iii) galvanic direct current (DC) + pulse current (PC). The skin samples were collected at different sampling points, extracted and analyzed by HPLC. Results suggested that the DC + PC mode for only 5 min was able to significantly increase the delivery of AA from o/w cosmetic compositions. The use of this current profile might improve the skin penetration of AA due to electromigration and passive diffusion, the latter being facilitated by the physical enhancement method. The SPC mode significantly improved the passage of EA in its neutral form from cosmetic o/w formulations by electroosmosis. Tailoring specific electrical current modes considering the ionization state of active ingredients would allow the design of short and personalized cosmetic treatments that significantly improve the penetration efficiency of the active ingredients and possibly reduce the doses applied.This research was entirely funded by L'Oreal, France.Cázares-Delgadillo, J.; Planard-Luong, L.; Gregoire, S.; Serna-Jiménez, CE.; Singhal, M.; Kalia, YN.; Merino Sanjuán, V.... (2018). Investigation of Different Iontophoretic Currents Profiles for Short-Term Applications in Cosmetics. Pharmaceutics. 10(4). https://doi.org/10.3390/pharmaceutics10040266266104R. Hamad, A.-W., Al-Momani, W. M., Janakat, S., & A. Oran, S. (2009). Bioavailability of Ellagic Acid After Single Dose Administration Using HPLC. Pakistan Journal of Nutrition, 8(10), 1661-1664. doi:10.3923/pjn.2009.1661.1664Kalia, Y. N., Naik, A., Garrison, J., & Guy, R. H. (2004). Iontophoretic drug delivery. Advanced Drug Delivery Reviews, 56(5), 619-658. doi:10.1016/j.addr.2003.10.026Marro, D., Kalia, Y. N., Begoña Delgado‐Charro, M., & Guy, R. H. (2001). Pharmaceutical Research, 18(12), 1701-1708. doi:10.1023/a:1013318412527Sobhi, R. M., & Sobhi, A. M. (2012). A single-blinded comparative study between the use of glycolic acid 70% peel and the use of topical nanosome vitamin C iontophoresis in the treatment of melasma. Journal of Cosmetic Dermatology, 11(1), 65-71. doi:10.1111/j.1473-2165.2011.00599.xHori, Y., Akimoto, R., Hori, A., Kato, K., Chino, D., Matsumoto, S., … Watanabe, Y. (2010). Skin collagen reproduction increased by ascorbic acid derivative iontophoresis by frequent-reversal bipolar electric stimulation. International Journal of Cosmetic Science, 32(3), 234-234. doi:10.1111/j.1468-2494.2010.00577_3.xJunyaprasert, V. B., Singhsa, P., Suksiriworapong, J., & Chantasart, D. (2012). Physicochemical properties and skin permeation of Span 60/Tween 60 niosomes of ellagic acid. International Journal of Pharmaceutics, 423(2), 303-311. doi:10.1016/j.ijpharm.2011.11.032Maia, A. M., Baby, A. R., Pinto, C. A. S. O., Yasaka, W. J., Suenaga, E., Kaneko, T. M., & Velasco, M. V. R. (2006). Influence of sodium metabisulfite and glutathione on the stability of vitamin C in O/W emulsion and extemporaneous aqueous gel. International Journal of Pharmaceutics, 322(1-2), 130-135. doi:10.1016/j.ijpharm.2006.05.03