Hechos, Mitos y Creencias sobre la Electricidad Atmosférica desde una Perspectiva Didáctica

Es indiscutible hoy el valor social de la educación en ciencias. Los fenómenos naturales observados desde temprano por los alumnos precisan explicaciones de naturaleza científica. Entre éstes está la electricidad atmosférica que, no obstante un fenómeno natural relativamente bien explicado en nuestros días, frecuentemente aparece asociado a ciertos mitos, temores y fantasmas, muchas veces sin ningún fundamento. En este artículo, se presentan algunos de los resultados de un estudio empírico que fue realizado precisamente sobre este tema, los intervenientes siendo alumnos del 8.º ano de enseñanza de dos escuelas del Alentejo, dos profesoras de Ciencias Físico-Químicas más los investigadores. En este estudio, inspirado en la etnografía, se empezó con la elaboración, por los alumnos, de un trabajo de averiguación sobre los hechos reales, mitos y creencias referentes a la electricidad con el propósito de, después de haber debatido en la aula sobre algunas de las limitaciones de estes elementos del conocimiento común, confrontar aquéllos con las explicaciones científicas correspondientes, planteadas a través de pequeñas anécdotas didácticas elaboradas por los investigadores

The Reflecting Heliometer of Rio de Janeiro after 6 Years of Activity

Started its regular, daily operational phase in 2011 and installed in 2009 by the occasion of the Symp264 in the XXVII IAU GA at Rio de Janeiro, the results so far obtained show that the Heliometer of the Observatorio Nacional fulfilled its planed performance of single measurement to the level of few tens of milli-arcsecond, freely pivoting around the heliolatitudes without systematic deviations or error enhancement. We present and discuss the astrometric additions required on ground based astronomic programs. We also discuss instrumental and observations terms, namely the constancy of the basic heliometric angle, against which the measurements are made, and the independence to meteorological and pointing conditions.Comment: 3 pages 2 double figures, proc. of IAU GA 2015 meeting no. 29, no. 224337

All-optical XOR based on integrated MZI-SOA with Co and counter-propagation scheme

“Copyright © [2009] IEEE. Reprinted from ICTON-MW 3rd. ISBN:978-1-4244-5745-8. This material is posted here with permission of the IEEE. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. By choosing to view this document, you agree to all provisions of the copyright laws protecting it.”In this work we present a review of all-optical XOR gates based on Mach-Zehnder Interferometer with Semiconductor Optical Amplifiers (MZI-SOA), using NRZ modulated signals driven at 10 Gbit/s. The performance of two alternative schemes for logical XOR gates implementation is demonstrated through numerical simulations and experimentally. The extinction ratio shows high operation performance with low degradation

Scoping the potencial for outdoor microalgae production in the Azores

Microalgae cultivation has received much attention due to some desirable characteristics such as fast growth rates, high photosynthetic efficiencies and the production of valuable biochemicals. Mass cultivation of microalgae for commercial purposes is already a reality in some locations being an activity with approximately 45 years. The Azores archipelago, located in the North Atlantic Ocean off the coast of Portugal, features a temperate climate. To evaluate the feasibility of local outdoor microalgae production, certain fundamental factors must be analysed. In this study water, light, temperature, carbon sources, nutrients, international outlook and regional context were analyzed from the perspective of a local outdoor commercial microalgae production. A SWOT analysis was applied to the analysed factors to evaluate the strengths, weaknesses, opportunities and threats. The results nominate the Azores as a promising location to implement an outdoor production of valueadded products from microalgae.Oma – Observatório do Mar dos Açores ; MARE – Centro de Ciências do Mar e do Ambiente ; IMAR – Instituto do Mar ; DOP – Departamento de Oceanografia e Pescas ; Universidade dos Açoresinfo:eu-repo/semantics/publishedVersio