Alternative mental models of second-year engineering students for Coulomb’s law and the electric field

El presente estudio tiene como objetivo identificar los modelos mentales que aplican los estudiantes al iniciar el segundo curso de ingeniería cuando utilizan la Ley de Coulomb y el concepto de campo eléctrico para interpretar fenómenos electrostáticos. Los resultados obtenidos indican que la mayoría de los estudiantes no aplica correctamente la simetría de la Ley de Coulomb. En general, el modelo mental de los estudiantes es coherente, pero no se ajusta al modelo aceptado científicamente. El modelo mental del estudiante confunde el concepto de campo eléctrico con el de fuerza entre cargas.Postprint (published version

Influence of the WeMO and NAO decadal trends on the airborne pollen levels recorded in Catalonia (NW Mediterranean basin)

Airborne pollen records constitute a powerful tool for different purposes. First, in studies of dispersion and source identification of pollen grains, which, incorporated into the atmosphere by anemophilous plants, produce allergic symptoms in a part of the population sensitive to it. On the other hand, aerobiological databases provide useful information for the understanding of the trends induced by the climate change. The decadal series allow the extraction of patterns with intra-annual variability (seasonality of the events and their relationship with the atmospheric transport patterns) and inter-annual variability (inter-annual trends and its possible relationship with climatic variability indexes). The longer the aerobiological monitoring series the better the understanding of the effects of climate change on pollination trends. The aim of this study is to explore the influence of climate change on the airborne pollen series recorded in Catalonia during the period 1994-2012 by the analysis of its correlation with both, the North Atlantic Oscillation (NAO) and the new regional teleconnection Western Mediterranean Oscillation (WeMO) defined within the synoptic framework of the western Mediterranean basin

Airborne pollen parameters and their relationship with meteorological variables in NE Iberian Peninsula

The present study explores the role of the meteorological variability in the pollen production and the timing of the airborne pollen season by analysis of the correlation between precipitation, insolation and temperature and the main standardised airborne pollen parameters of 22 taxa collected at 6 localities in Catalonia (NE Spain). The pollen parameters included in the study were: Annual Pollen Integral and the Start, End and Length of the Main Pollen Season. Considering that the Main Pollen Season of most of the taxa in Catalonia lasts from spring to summer or autumn, correlations between the pollen parameters and winter (from December to March) values of meteorological variables were calculated. Correlations between Monthly Pollen Integral and monthly values of the meteorological variables were also calculated. The results obtained report the synchronism registered in the variations of pollen concentration with precipitation (negative), insolation (positive) and temperature (positive). Temperature was the meteorological variable that showed a greater influence in the pollen production and the timing of the pollen season, being insolation the least one. The Start of the Main Pollen Season was the pollen parameter more correlated with the meteorological variables, especially with winter temperatures.Peer ReviewedPostprint (author's final draft

A multimedia-based course to learn basic acoustics through the Internet: description and evaluation

A course on Basic Acoustics has been implemented as an Internet site with multimedia resources such as Flash animations, video clips, etc. Multimedia resources are particularly suitable for acoustics, due to the special role played by sound. The constructivistic model of learning within the EHEA framework was taken as the most suitable approach. The students’ overall evaluation has been positive, especially as regards the embedded multimedia resources. Furthermore, many comments taken from their evaluations and assignments have helped to correct deficiencies and to improve the course.Postprint (published version

The Problem of Inconsistency in Reasoning in Engineering Education – A Case Study about the Mental Model of Sound

Every planning of an efficient teaching has the aim of achieving satisfactory learning outcomes. From a constructivistic point of view, it is a commonly accepted fact that such a planning has to take into account the prior ideas that students bring to the class. In order to know them, we carried out a survey about the prior ideas on the nature of sound that our fifteen third-year engineering students had at the begin of an elective subject on acoustics. We used a questionnaire where the students had to express their prior ideas with their own words. Although the students expressed scientifically accepted ideas in about 2/3 of the individual questions on a whole, a cross comparison between each student’s answers for the different scenarios revealed a great number of inconsistencies in the mental model of the nature of sound (wave model): only about 1/3 of our students were consistent in all these scenarios. The inconsistency in their reasoning was still clearer when each student had to apply his/her respective mental model about sound to several properties of sound, in particular the relationship between pitch and distance travelled by sound. We analyse the state of the art in the literature about the issue of students’ consistency, and we consider some proposals suggested in the literature, which we apply in part in our own teaching resources, in order to overcome this inconsistency problem.Postprint (published version

Relationship between climate variability indices and airborne pollination in Catalonia (NE Iberian Peninsula)

Here we explore the effect of climatic variability on the airborne pollen series recorded in Catalonia (NE Iberian Peninsula) considered of high interest due to abundance, landscape importance and/or allergenic significance. In this sense, the relationship between the annual and winter (December to March) phases of the North Atlantic Oscillation (NAO), the Western Mediterranean Oscillation (WeMO) and the Arctic Oscillation (AO) and the Annual Pollen Index (API), the start, the end and the length of the pollination seasons of 22 taxa collected at 6 aerobiological stations in Catalonia during the 18 years-period 1994-2011 have been computed. In addition, daily back-trajectories cluster analysis has been carried out in order to determine the influence of climatic indices on the main atmospheric transport routes frequencies and the long range pollen transport. Our aim is to determine the respective vulnerability of taxa to climate variability, taking also into account the pollen provenance area. Climatic indices showed significant negative correlations with the parameters API (except for Corylus) and pollination start (except for Ambrosia, Castanea, Fagus and Betula, the latter being Eurosiberian taxa often long range transported) of most taxa, while significant positive correlations with the end of the pollination period of most taxa. The most vulnerable taxa (more significant correlations) with regard to API were Corylus, Olea, Platanus and Quercus deciduous type.Postprint (published version

Transformació d’uns apunts tradicionals en un web hipertextual d’acústica

Peer Reviewe

Influence of synoptic meteorology on airborne allergenic pollen and spores in an urban environment in Northeastern Iberian Peninsula

The influence of the most frequent patterns of synoptic circulation on the dynamics of airborne pollen/spores recorded at the Barcelona Aerobiological Station (BCN) was analysed. Six pollen types (Platanus, Cupressaceae, Olea, Poaceae, Urticaceae and Amaranthaceae), and one fungal spore (Alternaria) were selected for their high allergenic effect in sensitive people. Six synoptic meteorological patterns were identified through cluster analysis of sea level pressure fields as the main responsible of the weather conditions in the Iberian Peninsula. The local meteorological conditions in Barcelona associated with each one of the synoptic types were also stablished. Different statistical methods were applied to analyse possible relationships between concentrations and timing of the recorded aerobiological particles and specific synoptic types. The study, focused in the 19-year period 2001–2019, shows that one of the scenarios, frequent in winter and linked to high stability and air-mass blockage, registered the highest mean and median values for Platanus and Cupressaceae, but it was not very relevant for the other taxa. It was also this scenario that turned out to be the most influent on the pollination timing showing a significant influence on the start occurrence of Urticaceae flowering and on the peak date of Platanus. On the other hand, the most frequent synoptic type in the period, relevant in spring and summer, was linked to sporadic episodes of levels considered to be of high risk of allergy to Platanus, Poaceae, and Urticaceae pollen, and Alternaria fungal spore. This synoptic pattern, characterized by the presence of the Azores anticyclone and the Atlantic low located in the north of the United Kingdom, was associated with high temperatures, low relative humidity and moderate winds from the NW in Barcelona. The identification of an interaction between synoptic meteorology and pollen/spore dynamics will allow better abatement measures, reducing adverse health effects on sensitive population.Peer ReviewedPostprint (published version

Entorn virtual d’aprenentatge autònom

En aquesta ponència presentem un Entorn Virtual d’Aprenentatge (EVA) dissenyat per fomentar l’aprenentatge autònom [1,2,3]. Es tracta d’una activitat dirigida en la qual se suggereixen les accions que l’estudiant ha de seguir per aprendre els conceptes relacionats amb la resolució de circuits elèctrics de corrent continu mitjançant l’aplicació de les lleis de Kirchhoff. Aquesta activitat forma part del curs de l’assignatura d’Electromagnetisme de les titulacions d’Enginyeria Industrial i Enginyeria Química de la UPC. Quan els estudiants van finalitzar l’activitat d’autoaprenentatge proposada, se’ls va demanar de respondre una enquesta d’opinió que ha estat analitzada i valorada.Postprint (published version

Potential contribution of distant sources to airborne Betula pollen levels in Northeastern Iberian Peninsula

Betula (birch) pollen is one of the most important causes of respiratory allergy in Northern and Central Europe. While birch trees are abundant inCentral, Northern, and Eastern Europe,theyare scarce inthe Mediterranean territories, especially in the Iberian Peninsula (IP), where they grow only in the northern regions and as ornamental trees in urban areas. However, the airborne birch pollen patterns in Catalonia (Northeastern IP) show abrupt high concentrations in areas withusually low local influence.The intensity of the derived health problemscan beincreasedbyoutbreaksdue to long-range pollen transport. The present work evaluates the different potential contributions to Catalonia from the main source regions: Pyrenees, Cantabria, and the forests of France and Central Europe. To this end, we computed the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back trajectories of air masses associated with the main Betula pollen peaks occurring simultaneously over different Catalan monitoring stations, and we studied their provenance over a 15-year period. The Vielha aerobiological station on the northern slopes of the Central Pyrenees was used to identify the dates of the pollen season in the Pyrenean region. In order to better understand the role of the Pyrenees, whichis thenearest of thefourbirch forested regions, weclassifiedthepollenpeaksinthe other Catalan stations into three groups based onthe relationship between the peak andthe pollenseason in thePyrenees. Our analysis of back-trajectory residence time, combined with the associated pollen concentration, reveals that two principal routes other than the Pyrenean forest sustain the northerly fluxes that enter Catalonia and carry significant concentrations of Betula pollen. This study has also allowed quantifying the differentiated contributions of the potential sourcePeer ReviewedObjectius de Desenvolupament Sostenible::3 - Salut i BenestarObjectius de Desenvolupament Sostenible::15 - Vida d'Ecosistemes TerrestresPostprint (published version