Search results for "[ SDE ] Environmental Sciences"
showing 10 items of 6671 documents
Tube transport of water vapor with condensation and desorption
2013
Attenuation and delay of active tracers in tube transport is an important current problem, but its full explanation is still lacking. To this end a model is introduced, where part of a tracer undergoes condensation and evaporation, treated as a diffusion-type process, in addition to Taylor dispersion. Condensation of water was verified by high-speed imaging, and the model solution fitted the breakthrough curves of laboratory measurements with pulses of water vapor of varying relative humidity. The model provides a transfer function whose performance was verified against field measurements. peerReviewed
Hydro-mechanical modelling of MX-80 bentonite: one dimensional study
2016
As a first step towards modelling the coupled Thermo-Hydro-Mechanical-Chemical (THMC) behaviour of bentonite, the Barcelona Basic Model (BBM) has been implemented into Numerrin finite element code. This model has been fully coupled with the single phase flow equation for unsaturated soils which models liquid water transport. Suction obtained from solving the flow equation is used as an input for the BBM model and the volumetric deformations from the mechanical analysis are used to update the pore water pressure field. As an alternative, BBM is used alongside the Kröhn’s model which assumes that bentonite re-saturation is mainly driven by water vapour diffusion. The paper simulates one dimen…
Iron and pH regulating the photochemical mineralization of dissolved organic carbon
2017
Solar radiation mineralizes dissolved organic matter (DOM) to dissolved inorganic carbon through photochemical reactions (DIC photoproduction) that are influenced by iron (Fe) and pH. This study addressed as to what extent Fe contributes to the optical properties of the chromophoric DOM (CDOM) and DIC photoproduction at different pH values. We created the associations of Fe and DOM (Fe-DOM) that cover the range of loadings of Fe on DOM and pH values found in freshwaters. The introduced Fe enhanced the light absorption by CDOM independent of pH. Simulated solar irradiation decreased the light absorption by CDOM (i.e., caused photobleaching). Fe raised the rate of photobleaching and steepened…
Global, National, or Market? Emerging REDD+ Governance Practices in Mozambique and Tanzania
2016
This article examines emerging governance practices in the REDD (Reducing Emissions from Deforestation and Forest Degradation) initiative. We examine three different general governance practices (neoliberal, post-national, and government-led practices) that have been applied in the interaction between international organizations and two REDD target countries: Mozambique and Tanzania. In these countries, we find that emerging REDD+ governance practices are a mixture of international organizations’ procedural practices and the target country’s established governance practices, whereas neoliberal practices are weakly expressed. These findings call into question the simplified assumption of re…
Is there a Nordic model of final disposal of spent nuclear fuel? Governance insights from Finland and Sweden
2017
This paper explores citizen participation in Swedish and Finnish regulatory processes for final disposal of spent nuclear fuel (SNF). Finland and Sweden are considered the most advanced worldwide in term of SNF disposal plans. Our aim is to analyze the institutional waste management frameworks, focusing on the role of civil society organizations (CSOs); how lay-people and civil society organizations have been able to participate and contribute to radioactive waste licensing processes; and the nature of radioactive waste risk debates. We review official documents of the waste companies and nuclear safety authorities, plus information from civil society organizations and laypeople. Our theore…
Perfil del futuro docente : nuevos retos en el marco del EEES
2019
En la actualidad, los nuevos requerimientos del siglo XXI en la formación docente son evidentes. El presente trabajo tiene como principal objetivo describir el perfil de los estudiantes universitarios en temas relevantes para su futuro profesional. Entre ellos se consideran importantes los enfoques de enseñanza, la atención a la diversidad, las TIC y su relación con el cyberbullying, la inteligencia emocional y la autoestima. La investigación fue llevada a cabo en la Universidad Católica de San Antonio de Murcia (UCAM) con una muestra de 230 estudiantes de Educación. Los instrumentos utilizados para este propósito fueron el cuestionario de autoestima Rosenberg, ATI, TMMS-24 y un instrumento…
Revista electrónica de investigación y evaluación educativa
2018
La victimización en la escuela representa un fenómeno preocupante dado las consecuencias negativas que se le asocian, como son estados de depresión o ansiedad, los cuales guardan relación con los hábitos de ocio digital. Se realizó un estudio descriptivo de tipo transversal, realizado en una muestra de 1038 escolares de tercer ciclo de Educación Primaria (M = 11,33; DT = 1,27), el cual persigue como principal objetivo contrastar un modelo explicativo del uso de televisión y videojuegos en función de la victimización. Se emplearon como principales instrumentos la Escala de Victimización en la Escuela (Mynard y Joseph, 2000), el Cuestionario de Experiencias Relacionadas con Videojuegos (Chama…
The Recurrent Characteristics of Historic Buildings as a Support to Improve their Energy Performances: The Case Study of Palermo
2017
Abstract The analysis of the recurrent characteristics of the local historic architecture is useful to develop large-scale energy analyses, regulations and financial strategies, but also to support technical guidelines for an energy improvement balanced with conservation. For this purpose, a multi-scale methodology ranging from envelope components to the urban dimension is necessary. In the research here exposed, this approach is investigated by focusing on the historic architecture of Palermo. For this heritage, the collection of thermal and hygrometric data for envelope components is combined with the examination of representative constructions, based on building stock categorization. Int…
High Frequency Data Acquisition System for Modelling the Impact of Visitors on the Thermo-Hygrometric Conditions of Archaeological Sites: A Casa di D…
2018
[EN] The characterization of the microclimatic conditions is fundamental for the preventive conservation of archaeological sites. In this context, the identification of the factors that influence the thermo-hygrometric equilibrium is key to determine the causes of cultural heritage deterioration. In this work, a characterization of the thermo-hygrometric conditions of Casa di Diana (Ostia Antica, Italy) is carried out analyzing the data of temperature and relative humidity recorded by a system of sensors with high monitoring frequency. Sensors are installed in parallel, calibrated and synchronized with a microcontroller. A data set of 793,620 data, arranged in a matrix with 66,135 rows and …
Phase equilibria of Pantelleria trachytes (Italy): constraints on pre-eruptive conditions and on the metaluminous to peralkaline transition in silici…
2018
Pantelleria Island is the type locality of pantellerite, an iron and alkali-rich rhyolite (P.I=molar Na2O+K2O/Al2O3 >1.05). Peralkaline rhyolites (i.e pantellerite and comendite) and trachytes usually represent the felsic end-members in continental rift systems (e.g., Pantelleria, Tibesti, Ethiopia, Afar, Kenya, Bain and Range, South Greenland) and in oceanic sland settings (Socorro Is., Easter Is., Iceland and Azores). The origin of peralkaline rhyolites in the different tectonic settings is still a matter of debate and three hypotheses have been suggested: (a) crystal fractionation of alkali-basalt in a shallow reservoir to produce a trachyte which subsequently gives rise to a pantelle…