Search results for "sostenible"
showing 10 items of 293 documents
La resistencia crítica
2008
ENGO TUNGO RINGO BINGO: Las políticas del cambio climático y las transiciones a sociedades poscarbono
2015
El título de este artículo tiene algo de irónico, pero no es inventado. Reproduce las denominaciones abreviadas de cuatro de los nueve grupos o sectores en que se clasifican los observadores acreditados de la sociedad civil para la cumbre del cambio climático en París (la COP21). Organizaciones no gubernamentales, respectivamente, ecologistas, sindicales, científicas y empresariales. De alguna manera, supongo, hay que poner orden en una babel donde se espera la presencia de cincuenta mil personas procedentes de las más diversas partes del mundo. De alguna manera hay que simplificar el barroquismo conceptual y lingüístico que inevitablemente tiende a imponerse en un contexto así. Pese a la d…
Triblock SEBS/DVB crosslinked and sulfonated membranes: Fuel cell performance and conductivity
2021
[EN] A set of styrene-ethylene-butylene-styrene triblock copolymer (SEBS) membranes with 10 or 25 wt.% divinyl-benzene (DVB) as a crosslinking agent were prepared and validated. Physicochemical characterization revealed suitable hydrolytic and thermal stability of photo-crosslinked membranes containing 25%wt. DVB and post-sulfonated. These compositions were evaluated in H2/O2 single cells, and electrical and proton conductivities were furtherly assessed. The membranes with the milder post-sulfonation showed greater proton conductivity than those with excessive sulfonation. In terms of electrical conductivity, a universal power law was applied, and the values obtained were low enough for bei…
Influence of substrate and temperature on the biodegradation of polyester-based materials: Polylactide and poly(3-hydroxybutyrate-co-3-hydroxyhexanoa…
2020
[EN] The extended use of polymers from renewable resources such as aliphatic polyesters or polyhydroxyalkanoates boosted the necessity to understand their behaviour in an end-of-life scenario. Although they can be degraded in reasonable shorter times than traditional polymers, understanding the degradation mechanisms under dissimilar conditions will contribute to further developments in this field. This work aimed to study the effect of temperature and substrate in the degradation of polylactide (PLA) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) in a simulated laboratory scale to ascertain their contribution, separately or in combination. For this purpose, nine parallel degradat…
Poly (lactic acid)/D-limonene/ZnO bio-nanocomposites with antimicrobial properties
2022
[EN] Antimicrobial films of poly (lactic acid) (PLA)/D-limonene/zinc oxide (ZnO)-based bio-nanocomposites were prepared via melt compounding and subsequent thermocompression. D-limonene was incorporated at concentrations of 10 or 20 wt%, and ZnO pure nanoparticles and those organically modified with oleic acid (O-ZnO), with an average diameter of 13.5 nm, were included at concentrations of 3, 5, and 8 wt%. The plasticizing effect of D-Limonene was corroborated by a decrease in the glass transition temperature compared to pure PLA. The presence of ZnO and O-ZnO in the PLA matrix promoted a slight increase in the degree of crystallinity due to its nucleant performance. Although ZnO and O-ZnO …
Química verda i sostenibilitat en l'educació científica
2017
En l’actualitat estem vivint una situació marcada per tota una sèrie de problemes estretament relacionats (contaminació i degradació d’ecosistemes, esgotaments de recursos, desigualtats creixents, conflictes...) Una situació que ja al 1991 el biòleg R. Bybee va qualificar d’autèntica emergència planetària. Aquest fet ha donat lloc a nombroses crides tant d’especialistes com d’organitzacions internacionals on es reclama la participació dels educadors de totes les àrees i nivells tant de l’educació formal com de la no reglada, per tal que contribuïm a formar ciutadans i ciutadanes conscients de l’actual situació d’emergència planetària i preparats per a participar en la presa de decisions. No…
The Press as a Resource for Promoting Sustainability Competencies in Teacher Training: The Case of SDG 7
2022
Given the seriousness of the socio-environmental situation we are facing, this study aims to contribute to the involvement of teachers in education for sustainability through the use of non-formal education, particularly the press. The main objectives of the present study are to analyse the use of the press in science education, as well as the design, implementation and evaluation of tools aimed at teachers and trainee researchers in order to encourage and promote attention to the Sustainable Development Goals (SDGs) and more specifically SDG 7 (clean and affordable energy for all) in science education. The proposals are carried out using a constructivist methodology in sessions structured …
La comprensión e impulso de la Sostenibilidad: un requisito imprescindible para una acción educativa y ciudadana eficaz
2019
Diagnósticos concordantes de la actual situación de emergencia planetaria muestran la necesidad de una urgente transición a sociedades que hagan posible una vida justa y digna al conjunto de seres humanos y a las futuras generaciones, al tiempo que se protege la biodiversidad y se revierte la degradación del medioambiente. Esta problemática ha dado lugar a propuestas con distintas denominaciones -transición a la sostenibilidad, decrecimiento, crecimiento inclusivo… - generando controversias que pueden dificultar el establecimiento de una agenda común para hacer frente a los problemas. Proponemos por ello centrar el debate en analizar las medidas que se consideran necesarias, en particular p…
Towards breaking the Gender Gap in Science, Technology, Engineering and Mathematics
2020
The gender gap in Science, Technology, Engineering and Mathematics (STEM) has drawn the attention of research and academic communities due to its impact in the Digital Society, targeting the fourth and fifth 2030 sustainable development goals of achieving quality education and gender equality. Recent studies show that women are enrolling STEM studies in smaller proportion than men and that they have a larger probability to renounce to their jobs or to take leaves. In this scenario, the involvement of educational institutions is seminal to change this trend. The School of Engineering of the University of Valencia (ETSE-UV), Spain, launched in 2011 a pilot program to promote STEM careers, foc…
Direct assessment of the sensitivity drift of SQM sensors installed outdoors
2021
Long-term monitoring of the evolution of the artificial night sky brightness is a key tool for developing science-informed public policies and assessing the efficacy of light pollution mitigation measures. Detecting the underlying artificial brightness trend is a challenging task, since the typical night sky brightness signal shows a large variability with characteristic time scales ranging from seconds to years. In order to effectively isolate the weak signature of the effect of interest, determining the potential long term drifts of the radiance sensing systems is crucial. If these drifts can be adequately characterized, the raw measurements could be easily corrected for them and transfor…