A closed-form solution to predict short-range surface plasmons in thin films and its application to hole arrays

A theoretical study of surface plasmon polaritons (SPPs) in ultrathin lossy metal films is presented. The dispersion relation of such films is well known and can be solved numerically to obtain a combination of long-range (LR-) and short-range (SR-) eigenmodes. In this contribution, a simple solution for the SR-SPPs is derived. An approximation for the LR- eigenmodes can be found elsewhere. To validate the approximation, a two dimensional (2D) periodic array of small holes is studied subsequently. The spectral response of the array is obtained by full-wave simulations and the results compared with those calculated analytically, showing an excellent agreement for small holes

The impact of the generation mix on electricity market prices: a comparative analysis at European level ​

The goal of this thesis is to investigate the impact of non-programmable renewable energy generation mix on Italian and Spanish electricity markets by studying electricity price in the spot electricity market. Specifically, to investigate whether different energy sources have a different impact on the price, whether and or how much this is varying from different market zones and whether the impact is on general, daily-basis or maybe rather on an hourly basis. To detect the impact on electricity prices, it is followed a consolidated methodology adopted by Clò et al. [1] and developed an empirical analysis for Italy’s commercial markets and for the whole Spanish market by using a multivariate regression. It is considered daily averaged data for the renewable generation mix (specifically solar and wind) and spot electricity price from the respective day-ahead markets for the whole year 2018. As a secondary studio the impact on electricity prices in Italy is analysed by using hourly data. The results obtained support the hypothesis that rising zonal loads tend in general to raise zonal market prices based on the data from 2018. The intensity of this effect is pronounced with varying intensity. In Italy the lowest effect is in the North, with an impact of 1.19 €/MWh increase for each 1000 MWh of demand. The highest effect is found in the islands, reaching a value of 25.11 €/MWh in Sicily. In Spain, there is a low impact of load, with a value of only 0.045 €/MWh. It is interesting to stress how the impacts of photovoltaics and wind vary across Italian zone. While both prove to have in general a decreasing impact, on the electricity spot price, wind is the main driver of the electricity price reduction in the southern zonal areas whereas solar has a more significant decreasing impact on the northern zone prices. Eventually, Central North is the zone with the highest impact of both renewable sources. In Spain, no evidence is found for photovoltaics for electricity price reduction. But, on the other hand, an increase of 1 GWh of wind decreases the Spanish electricity price by 1.42 €/MWh. The results obtained also show for both Italy and Spain the assumption of high correlation between the price of gas and electricity: an increase of 1 €/MWh of gas price causes statistically an electricity price increase between 0.90 €/MWh and 1.73 €/MWh in Italy (depending on the zone) as well as an increase of 1.76 €/MWh in Spain. Compared to the daily data case, results of the secondary analysis show that solar comes out significant in all zones of Italy. Energy from solar panels is obtained only a few hours a day, therefore it turns out that the impact seems to be stronger on an hourly basis. However, wind has rather a daily impact, being wind generation more constant from day to day also not having such a plausible difference between hours as solar.Outgoin

Synthesis and design of periodic mm- to nano-scale gratings and their application in antenna systems

This thesis investigates the application of 2D periodic arrays of passive elements for future millimetre and nanometre waves antenna applications, and aims to provide guidelines for researchers dealing with the electromagnetic response of this type of structures in next generation communication systems. Novel configurations are here reported driven by the power requirements at each frequency band, as well as adapted analysis methods for its synthesis and analysis. All-dielectric structures based on form-birefringence and gradient index optics are considered in the first part of this dissertation, for their application to highly di rective circularly polarised antennas for transmission and reception of high power millimetre waves. Higher frequency nanometre waves are the focus of the second part, where the utilisation of 2D arrays of metallic nanoparticles as building blocks for optical leaky wave and magnetic antenna systems is thoroughly studied.Funded by EPSRC (Engineering and Physical Sciences Research Council

Treatment of impacted or retained second molars with the miniscrew-supported pole technique: a prospective follow-up study

Background: Eruption disturbances of permanent molars are uncommon; however, it is important to treat them as soon as they are diagnosed. The main objective was to analyze the effectiveness of the “miniscrew-supported pole technique,” a surgically assisted orthodontic procedure to force the eruption of impacted/retained second molars (M2s) when there are indicators of complex molar inclusion. An observational prospective study was carried out during a 2-year period. Sociodemographic, clinical and low-dose scanner variables were taken at baseline (T0). Follow-up variables (T1) were the time between surgery and tooth eruption, radiographic measurements, debonding of buttons, failure rate of miniscrews and success rate of eruption. Results: A total of 21 patients (mean age of 13.9 years) with 24 retained/impacted M2s were recruited; 13 molars were maxillary (54.2%) and 11 (45.8%) were mandibular. Six (25%) were impacted molars and 18 (75%) primarily retained. At T0, molar angulation was mesial in six molars (25%), distal in five molars (20.8%) and 13 molars were vertically positioned (54.2%). Infraocclusion degree was moderate in four (16.7%) molars and severe in 20 (83.3%). Only three (12.5%) third molars were removed due to lack of space. All M2s managed to erupt, achieving a success rate of 100%; however, two molars of the same patient did not achieve occlusion. The period of eruption after surgery was 126.8 (117.3) days. Anatomical radicular alteration was the only variable independently related to a longer time of treatment (p = 0.027). Conclusions: The pole technique, using one mesial miniscrew and simple orthodontic mechanics, applies forces that succeed in erupting complicated retained/impacted M2s in a short period of time and with a low failure rate

Treatment of impacted or retained second molars with the miniscrew-supported pole technique: a prospective follow-up study

Ectopic eruption; Molar angulation; Surgical procedureErupción ectópica; Angulación molar; Procedimiento quirúrgicoErupció ectòpica; Angulació molar; Procediment quirúrgicBackground Eruption disturbances of permanent molars are uncommon; however, it is important to treat them as soon as they are diagnosed. The main objective was to analyze the effectiveness of the “miniscrew-supported pole technique,” a surgically assisted orthodontic procedure to force the eruption of impacted/retained second molars (M2s) when there are indicators of complex molar inclusion. An observational prospective study was carried out during a 2-year period. Sociodemographic, clinical and low-dose scanner variables were taken at baseline (T0). Follow-up variables (T1) were the time between surgery and tooth eruption, radiographic measurements, debonding of buttons, failure rate of miniscrews and success rate of eruption. Results A total of 21 patients (mean age of 13.9 years) with 24 retained/impacted M2s were recruited; 13 molars were maxillary (54.2%) and 11 (45.8%) were mandibular. Six (25%) were impacted molars and 18 (75%) primarily retained. At T0, molar angulation was mesial in six molars (25%), distal in five molars (20.8%) and 13 molars were vertically positioned (54.2%). Infraocclusion degree was moderate in four (16.7%) molars and severe in 20 (83.3%). Only three (12.5%) third molars were removed due to lack of space. All M2s managed to erupt, achieving a success rate of 100%; however, two molars of the same patient did not achieve occlusion. The period of eruption after surgery was 126.8 (117.3) days. Anatomical radicular alteration was the only variable independently related to a longer time of treatment (p = 0.027). Conclusions The pole technique, using one mesial miniscrew and simple orthodontic mechanics, applies forces that succeed in erupting complicated retained/impacted M2s in a short period of time and with a low failure rate

Iniciación del desarrollo profesional de los docentes de Educación Primaria (Argentina, Colombia, España y Francia). Estudio comparado.

Uno de los aspectos fundamentales en la consecución de una educación de calidad es la figura del maestro, su formación y su forma de intervenir en las aulas de educación primaria en tanto en cuanto la profesionalidad de los docentes puede marcar la diferencia en el aprendizaje de los estudiantes incluso contrarrestando las dificultades de origen. De hecho: 'Las escuelas que desafían sus condiciones adversas y logran buenos resultados de aprendizaje son aquellas en las que los docentes han asumido una mayor participación en la toma de decisiones institucionales y un mayor compromiso con los resultados de aprendizaje de los alumnos (OREALC/ UNESCO, 2007, p.60)'. Por todo ello, desde este planteamiento, pretendemos analizar comparativamente los sistemas de formación e iniciación al desarrollo profesional (en su fase de inducción) de los docentes de primaria de Argentina y Colombia -con respecto a Latinoamérica- y España y Francia -con respecto a Europa. Seleccionamos esta muestra de países en la medida que consideramos que cumplen criterios de similitud mínimos, así como suficientes diferencias como para enriquecer la comparación. Para ello partiendo de variables como modelo formativo, formación previa a la iniciación docente, estructura de la formación e iniciación de su desarrollo profesional, realizamos una comparación cuyos resultados apuntan a la relación entre los modelos de formación y de acceso al trabajo y la repercusión cualitativa de la intervención en las aulas. One of the key aspects in achieving quality education is the figure of the teacher, their training and how to intervene in elementary classrooms as long as the professionalism of teachers can make a difference in student learning even counteracting the difficulties of origin. In fact, schools that challenge their adverse conditions and achieve good learning results are those in which teachers have assumed greater participation in institutional decision-making and commitment to the results of student learning (OREALC / UNESCO, 2007, p. 60). Therefore, from this approach, we intend to analyze comparatively training systems and initiation to professional development (in their induction phase) of the primary teachers of Argentina and Colombia, with regard to Latin America- and Spain and France, with respect to Europe. We selected this sample of countries as we consider that meet minimum criteria of similarity and enough differences to enrich comparison. To do this based on variables such as training model, prior to teaching initiation formation, structure formation and initiation of their professional development; we make a comparison whose results point to the relationship between training models and access to work and qualitative impact intervention in the classroom

Disseny i millora de la bateria d’un vehicle elèctric de competició per la Formula Student

L'objectiu principal d'aquest projecte és donar a conèixer l'evolució en les darreres dues temporades del connexionat de potència. Es presentaran les raons que van donar lloc al disseny de la bateria pel CAT09e i s'estudiaran amb un seguit de proves en el laboratori d'electrònica de potència les diferents possibilitats de millora del disseny d'aquest connexionat. Finalment es decidirà la opció més òptima a introduïr a la nova bateria, aquest cop per al CAT10e. A més, la bateria està monitoritzada per un Battery Management System, BMS, que s'encarrega de controlar la tensió de cada cel·la i la seva temperatura. Aquest serà també un dels altres punts d'atenció d'aquest projecte. Es presentarà un canvi important d'aquest sistema que va patir el CAT08e i que es va mantenir per al CAT09e, el pas d'una tipologia descentralitzada a una centralitzada, que va permetre reduir el nombre de components que el formen, facilitar el muntatge i reduir possibles problemes alhora d'interactuar amb la bateria. S'explicarà també el mode d'implementació d'aquest sistema al nou package de bateries del CAT10e i totes les consideracions necessàries per garantir un bon funcionament. És propòsit d'aquest projecte informar dels possibles errors de disseny i fabricació sorgits, així com les recomanacions rebudes per part dels inspectors de la competició. Especialment aprofitant la creació d'una nova fase de verificacions anomenada Accumulator check en la competició de Formula Student Germany, una fase prèvia a la inspecció elèctrica del cotxe on les bateries dels equips són avaluades en termes de seguretat per l'organització de la competició. Avaluació per on va passar la bateria del CAT08e

Unravelling the Photoprotection Capacity of Resveratrol on Histidine Oxidation

Exposure to sun radiation causes great oxidative stress and activates a numerous of defense mechanisms in living systems, such as the synthesis of antioxidants. Resveratrol (RSV), a naturally occurring stilbene molecule, has antioxidant properties and is synthesized in large amounts when plants are under high oxidative stress. Likewise, under UV and visible radiation, biomolecules are oxidized, losing their physiological properties and, therefore, avoiding the harmful effects of solar radiation is crucial in order to preserve the functionality of cellular components. In proteins, one essential component that is often susceptible to degradation is the amino acid histidine (His), which can be modified via several oxidizing mechanisms. In this article, we evaluate the photoprotection capacity of RSV in photosensitized oxidation of His, which is initiated with a one-electron transfer reaction, yielding the His radical cation (His•+). The photoprotective properties of RSV are evaluated using kinetics analysis during steady-state irradiation and laser flash photolysis experiments. The experimental results reveal that the presence of RSV in the solution causes an evident decrease of the His consumption initial rates as a result of a reaction between His•+ and RSV that recovers the amino acid. In addition, we conclude that during its antioxidant action, RSV is consumed being a sacrificial antioxidant.Fil: Neyra Recky, Jael Rhode. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Dantola, Maria Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Lorente, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

Continuous monitoring of volatile organic compounds through sensorization. Automatic sampling during pollution/odour/nuisance episodic events

Volatile organic compounds (VOCs) are a highly diverse class of chemical contaminants and between 50 and 300 of them may be found in ambient air. In urbanized areas, VOCs are emitted from industrial activities, as well as from vehicle-related and combustion sources. VOCs outdoors can be detected in a broad range of concentrations, usually varying seasonally. The presence of VOCs at relatively high concentrations has been related to poor air quality, discomfort and odorous nuisances. Additionally, they can have negative health effects to the human organism. Hence, in locations where recurrent sporadic situations of high VOCs levels take place, episodic samples' evaluation is necessary instead of 24 h or longer sampling period's evaluations. The use of commercially available metal oxide semiconductor gas sensors for a continuous monitoring of VOCs concentrations in outdoor air is an interesting and innovative technology. Additionally, the use of these sensors for the activation of a VOCs sampler when episodic events of nuisance/odorous annoyance occur was successfully evaluated. The sensor activation is induced by higher VOCs concentrations from a wide number of VOC chemical families. Two sensor stations, developed at our laboratory and provided with sampling pumps, were located in the municipality of Santa Margarida i els Monjos (Catalunya, Spain) in January 2021. The stations started recording data continuously from two different types of VOCs sensors, temperature, relative humidity and pressure in 1.5-min periods. Automatic VOCs sampling was conducted, using multi-sorbent bed tubes, during the months of June–July when the sensors electronic values exceeded a set point value. Samples were analysed through TD-GC/MS. TVOC concentrations in episode samples ranged between 78-669 and 12–159 µg m-3 in Site 1 and Site 2, respectively. Although TVOC concentrations were not high in all cases, relevant concentrations of chloroform were observed, especially in Site 1, with concentrations ranging from 19 to 159 µg m-3.Postprint (published version