Optimal Fiscal Policy and the (Lack of) Time Inconsistency Problem

Time-consistency, Markov Equilibrium, Public Debt

Pollution of alpine ponds and groundwater by de-icing chemicals (Serra da Estrela, Central Portugal)

The ecological and socioeconomic importance of mountains is being increasingly recognised. Such regions provide key ecosystem services, namely, water supply which benefits local as well as lowland human populations. Besides mountain aqui fers and rivers, alpine lakes and ponds are crucial for water resources management but are also important in hydroecological and wildli fe conservation terms. This study aims at comparing the pollution of surface and underground water bodies by de -icing chemicals in a mountain environment. The influence of geological, geomorphological, pedological, climatic and anthropic conditions is taken into account. The study region is the highest part of the Serra da Estrela, a Mediterranean mountain located in Central Portugal. In this area there is a hydrological system which encompasses water-table aquifers and number of alpine ponds of glacial origin situated between 1500 m a.s.l. and the summit (1993 m a.s.l.). In the study area, the alpine ponds and springs were inventoried. Water sampling campaigns were carried out for hydrogeochemical characterisation of alpine ponds. These results were compared with hydrogeochemical data from water springs obtained in previous studies. Concentration of the following analytes were determined- total organic carbon (TOC), metals (Pb, Zn, Fe, Cu, Ni, Cd, Cr, As, Mn), cations (Na+, K+, Ca2+, Mg2+), anions (F-, CI-, NO3-, SO42-), silica (SiO2) and nutrients (N, P). Additionally, parameters such as pH, conductivity, turbidity and alkalinity were also measured. The hydrogeochemistry of ponds and water table aqui fers affected by de-icing chemicals is clearly different from the one showed by non-polluted water bodies, due to the influence of different physical settings as well as to the spatial distribution of the anthropic influence. The pond and aqui fer contamination affects water quality but may also disturb the local highly sensitive aquatic ecosystems.N/

Characterization of wind-blown sediment transport with height in a highly mobile dune (SW Spain)

The Valdevaqueros dune is located at one of the windiest points of Europe, where the frequent occurrence of strong easterly winds has generated a highly mobile dune. Several rotating cup anemometers in vertical array and a self-designed vertical sand trap, were placed to retain the drift sands at different heights over the surface in order to determine theoretical and actual sand transport rates in the Valdevaqueros dune system. General results show that 90% of the wind-blown sand is transported within the first 20cm above the dune crest surface. Theoretical transport rates based on different empirical formulae were 0.33 to 0.78 times the in-situ sand transport rate detected, which was 2.08·10-2kgm-1s-1 under moderate wind power (mean speed ranging from 8.4 to 17.9ms-1). Analysis of different statistical grain-size parameters helped to understand sand transport distribution at different heights

Teaching Calculus with Infinitesimals: New Perspectives

The present research corroborates K. Sullivan\u27s initial results as stated in her epoch making study about the effectiveness of teaching elementary calculus using Robinson\u27s non standard approach. Our research added to her results related to the teaching of the elementary integral, with similar positive results. In this essay we propose a definition of the notion of cognitive advantage mentioned by Sullivan in expressing the dramatic differences in understanding of students of non standard calculus as opposed to those of its standard counterpart. Our proposal is based on ideas of Kitcher and Kuhn and allows us to better understand the didactics of Calculus. Formally K. Sullivan\u27s claim of an observed advantage when referring to the improved understanding of non standard calculus students (as opposed to the standard approach of Weierstrass) is a consequence to the accepted fact that mathematical truths remain the same when changes of paradigms ensue, a situation markedly different from that science. While mathematical truths remain, mathematical justifications (proofs) change dramatically and increase in complexity

Chemical analysis and characterization of biomass for biorefineries

The aim of this chapter is to offer different chemical analyses and character-ization options for researchers or whoever is looking for an appropriate methodology to analyze results obtained in laboratory tests, especially assuming the challenge to find the best process to achieve bio-products under biorefinery concept. In this way, the information provided will be very useful to evaluate the results and moreover, to improve the research process. That is the reason why analytical techniques to charac-terize different lignocellulosic biomass are described with detailed data about its prin-ciples and methodology, emphasizing either physical or chemical protocols that are followed normally in research laboratories. Taking into account that lignin, cellulose, and hemicelluloses are the principal compounds of these kinds of raw materials, which in general are residues, the information is emphasized with that target of analysis. Nevertheless, as it is possible to obtain a lot of bio-products from biomass, like sugars, alcohols, aromatics, biopolymers and so on, other analytical methods are includedPrimera edició

COMPOSTO PARA RESTAURANTES: ATENDENDO CONSUMIDORES COM DEFICIÊNCIA VISUAL

As pessoas com deficiência (PcD) enfrentam diversas dificuldades para exercerem quase todos os papéis sociais, especificamente no que diz respeito ao papel de consumidores. Raramente, essas pessoas têm suas necessidades atendidas. No Brasil, tal mercado está representado por 24 milhões de PcD, das quais 48% têm deficiência visual. Na presente pesquisa, definiu-se como objetivo identificar os mais importantes atributos do serviço e seus níveis correspondentes, relativos à experiência de consumo por pessoas com deficiência visual em restaurantes da cidade do Rio de Janeiro, em ocasiões de lazer. Para atingir esse objetivo, foram realizados três grupos de foco com a participação de 21 PcD. Os resultados apontaram oito atributos, cada qual apresentando três ou dois níveis como mais importantes para a experiência de consumo de deficientes visuais em restaurantes: “cardápio”; “atendimento”; “ambiência”; “formato da mesa”; “acesso ao garçom”; “nível de ocupação”; “local”; e “comida”. A partir desse resultado, percebe-se que os restaurantes não estão preparados para receber pessoas com deficiência visual

Prediction of the acoustic insulation of a prefabricated wooden-based system for collective buildings

Using wood, a renewable, carbon sink material with outstanding thermal properties associated with the prefabrication process and its benefits, a construction system for multi-storey multifamily buildings based on prefabricated wooden panels was developed to act as a tool for meeting the national carbon neutrality targets. It will contribute to the promotion of increasingly sustainable cities that optimise the use of materials and rely on highly energy-efficient buildings. This sustainable alternative to conventional construction materials was designed to comply with the Portuguese needs, regulations, and regulatory requirements regarding construction, structural, functional, and logistics demands. As the acoustic behaviour of wooden buildings is a sensitive subject due to the wood's lightweight and poor insulation performance for low-frequency sounds, this work aims to analyse the panels regarding their acoustic behaviour through INSUL software. The predictions showed favourable results for airborne insulation and partially favourable for impact sound insulation.This work was supported by national funds through FCT – Fundação para a Ciência e a Tecnologia, within the scope of a Ph.D. scholarship (PRT/BD/152841/2021) granted by MIT Portugal Program to the first author

Habilidades comunicativas en estudiantes de carreras de apoyo frente a estudiantes de otras carreras

El presente trabajo pretende comprobar las habilidades de comunicación de los estudiantes universitarios y la importancia profesional que les otorgan; al tiempo que observar si existen diferencias entre los estudiantes de carreras de apoyo frente a los de otras carreras.Participaron 418 estudiantes de distintos grados y másteres de la Universidad de La Laguna. Se realizó un análisis de frecuencia para determinar el nivel de uso e importancia otorgada a las habilidades comunicativas y una prueba T para muestras independientes con el objetivo de observar las diferencias entre los dos grupos. La información se recogió mediante el cuestionario de habilidades comunicativas para profesionales HABICOM. Los resultados indican que los estudiantes universitarios utilizan habilidades adecuadas y dan importancia a éstas en el desempeño profesional; aunque los estudiantes de carreras de apoyo destacan frente a los de otras carreras; sin embargo son resultados que deben tomarse con cautela debido al escaso tamaño del efecto. Consideramos necesario continuar la formación en estas habilidades a los estudiantes universitarios, ya que son fundamentales para su desempeño profesional.This paper aims to verify the use of the communication skills from university students and professional importance they given them; and examine whether there are differences between students of support degrees and students of other degrees. It was attended by 418 students of various degrees and Master’s degrees from the University of La Laguna. In the study, a frequency analysis was employed to determine the level of use of communication skills and importance they given them; and a T test for independent samples in order to observe the differences between two groups. The information was collected by questionnaire for professional communication skills HABICOM. The results show that college students use appropriate communication skills and give importance to them in their careers, although students of support degrees stand out from those of other degrees; however results are to be taken with caution due to the small effect size. We consider it’s necessary to continue training in these skills to college students because they are fundamental for their professional performance