Two-ballot versus plurality rule: an empirical investigation on the number of candidates

Duverger claimed more than 50 years ago that the number of candidates in elections should be a function of electoral rules. Both his “law” and “hypothesis” suggest the number of candidates vying for seats in elections to be tightly linked to characteristics of the electoral process such as its degree of proportionality and the presence of runoffs. Here we test the validity of Duverger’s claim using data from municipal elections in Brazil. Our study differs from others in the field in two important dimensions. First, by using municipal data we avoid the usual problems that plague statistical analysis using cross-country data. Secondly, we have a truly exogenous source of variation due to a change in electoral legislation introduced by the constitutional reform of 1988: simple plurality remained the rule only in municipalities with less than 200,000 voters, and a second-ballot became mandatory for the others above that threshold. This allows for a neat identification strategy using panel data. Our main finding is that elections with runoffs lure greater numbers of candidates in municipalities with sufficiently high levels of heterogeneity.Duverger's law, runoff, heterogeneity

Conflict behavior and conflict management in the organizations

Some people think conflict is a topic that should not be discussed and that we should not engage in conflict. Productively engaging in conflict is always valuable. Most people are willing and interested in resolving their conflicts; they just need the appropriate skill set and opportunities in which to practice this skill set. Without a conflict skill set, people want to avoid conflict, hoping it will go away or not wanting to make a “big deal out of nothing.” Research and personal experiences show us that, when we avoid conflict, the conflict actually escalates and our thoughts and feelings become more negative. Through conflict self-awareness we can more effectively manage our conflicts and therefore our professional and personal relationships. Furthermore, by discussing issues related to conflict management, teams can establish an expected protocol to be followed by team members when in conflict. All teams and organizations have a conflict culture (the way the team responds to conflict). However, most teams never discuss what the conflict culture is, therefore providing the opportunity for individual team members to make assumptions that can be counterproductive to the team. Practicing one’s conflict management skills leads to more successful engagement in conflict with outcomes of relief, understanding, better communication, and greater productivity for both the individual and the team. When we manage our conflicts more effectively, we use less energy on the burdensome tasks such as systemic conflict and get to spend more of our energy on our projects at work and building our relationships

Study of tribological properties of moulds obtained by stereolithography

Stereolithography (SL) is a process that allows the rapid manufacturing of high-accuracy rapid tools using an ultraviolet laser beam to polymerize a liquid resin, layer-by-layer. In this work, the friction properties of commercial SL resins in contact with several thermoplastics were assessed. Friction experiments were done with plastics overmoulded onto moulding blocks made from SL resins. It was observed that polymers with Hildebrand solubility parameters close to the resins showed adhesion characteristics that were not observed in polymers with values of this parameter further apart.EU Programme ALFA (project Plastinet-master

Avaliação experimental de metodologia de ensaio acelerado de exposição à chuvas dirigidas

A sustentabilidade de um material está relacionada diretamente a sua durabilidade, pois, quanto maior a vida útil de um produto, menor será a necessidade de sua reposição como um todo ou de seus elementos constituintes. Entretanto, a durabilidade não é uma propriedade restrita ao material e irá depender, principalmente, da sua interação com o ambiente que o cerca, sendo de extrema importância o conhecimento dos agentes de degradação a que estará submetido quando em condições de uso. Nesse contexto, a chuva dirigida, chuva associada à velocidade do vento, é considerada um dos fatores de maior degradação em vedações externas, podendo acarretar à edificação desde problemas estéticos causados pela infiltração de umidade até a decomposição dos materiais que compõem as fachadas e alvenarias. Testes experimentais acelerados, propostos por normas internacionais, objetivam avaliar a erodibilidade em construções de terra quando expostas à chuva, porém, em virtude das recentes pesquisas abordando a utilização de resíduos e aditivos na produção de elementos para alvenarias, se faz necessária a adaptação de metodologias para a avaliação desses novos materiais. Neste documento é relatada uma pesquisa experimental objetivando analisar a influência do metacaulim na durabilidade de blocos vazados de concreto para alvenarias, sendo esta avaliada por meio de ensaio acelerado de exposição à chuivas. De acordo com a metodologia do ensaio, duas horas de exposição permitem avaliar a erosão pluvial ocorrida em 50 anos, considerando os parâmetros climatológicos mais agressivos de Portugal (localidade de Penhas Douradas) sendo a erodibilidade, medida pela perda de massa ocorrida durante o ensaio, utilizada como parâmetro de resposta. O teor de cimento nas misturas foi de 12% e o metacaulim foi utilizado em substituição parcial à massa do cimento nos percentuais de 10% e 15%. Corpos de prova prismáticos foram submetidos ao ensaio aos 56 dias de cura, quando também foram realizadas análises termogravimétricas (TGA) para investigação das alterações químicas decorrentes da adição do metacaulim. Os melhores resultados foram obtidos para as misturas com 15% de metacaulim, cujos corpos de prova apresentaram perda de massa 23% inferior aos corpos de prova de referência, sem metacaulim, apresentando também menor ocorrência de carbonatação, o que foi comprovado por meio das análises termogravimétricas. Os baixos valores de perda de massa (<1%) para todas as misturas demonstraram que, para o estudo de durabilidade de concretos expostos à ação de chuvas, a erodibilidade, associada ao ensaio de chuva dirigida utilizado, não pode ser considerada como parâmetro de resposta. Concluiu-se também que, a secagem em estufa (100±5o C) para obtenção dos valores de massa seca, pode promover maior carbonatação devendo todas as amostras, ensaiadas ou não, permanecer por igual período de tempo em estufa.Os autores agradecem o apoio financeiro do CNPq – Conselho Nacional de Desenvolvimento Científico e Tecnológico (248888/2013-7) e aos integrantes do Laboratório de Materiais de Construção da Universidade do Minho. Agradecem também ao Prof. Fernando Castro, coordenador do Laboratório de Metalurgia do Departamento de Mecânica da Universidade do Minho e ao técnico Miguel Abreu, pela execução das análises térmicas.info:eu-repo/semantics/publishedVersio

Recent advances on materials for lithium-ion batteries

Environmental issues related to energy consumption are mainly associated with the strong dependence on fossil fuels. To solve these issues, renewable energy sources systems have been developed as well as advanced energy storage systems. Batteries are the main storage system related to mobility, and they are applied in devices such as laptops, cell phones, and electric vehicles. Lithium-ion batteries (LIBs) are the most used battery system based on their high specific capacity, long cycle life, and no memory effects. This rapidly evolving field urges for a systematic comparative compilation of the most recent developments on battery technology in order to keep up with the growing number of materials, strategies, and battery performance data, allowing the design of future developments in the field. Thus, this review focuses on the different materials recently developed for the different battery components—anode, cathode, and separator/electrolyte—in order to further improve LIB systems. Moreover, solid polymer electrolytes (SPE) for LIBs are also highlighted. Together with the study of new advanced materials, materials modification by doping or synthesis, the combination of different materials, fillers addition, size manipulation, or the use of high ionic conductor materials are also presented as effective methods to enhance the electrochemical properties of LIBs. Finally, it is also shown that the development of advanced materials is not only focused on improving efficiency but also on the application of more environmentally friendly materials.Funding grants UID/FIS/04650/2020, UID/EEA/04436/2020 and UID/QUI/0686/2020; and project PTDC/FIS-MAC/28157/2017. Financial support grants SFRH/BD/140842/2018 (J.C.B.) and Investigator FCT Contracts CEECIND/00833/2017 (R.G.) and 2020.04028.CEECIND (C.M.C.) Financial support ELKARTEK and PIBA (PIBA-2018-06) programs

A miniaturized self-calibrated pyrometer microsystem

paper describes the design, modeling and optimization of a miniaturized self-calibrated pyrometer to detect infrared radiation (in 5-20 µm range of wavelengths) in order to measure the real temperature of objects without contact. The microsystem consists of a thermally insulated absorbing area and two thermopiles with the hot junctions in the absorbing area and the cold junctions on a heat sink (i.e. the silicon bulk). The complete microsystem is in silicon planar technology and each thermopile has a different reference temperature, biased by a Peltier microstructure near to the cold junction of the thermopile. A silicon die passivated with a silicon nitride membrane is the ground floor of all microsystem. The absorbing area, a black gold strip on the silicon nitride membrane is obtained by anisotropic etching of the bulk silicon from the back of the wafer. The pyrometer microsystem is composed by: the IR optical filter on the top, the electronic system built in CMOS technology added by Multi-Chip-Module (MCM) techniques and the pyrometer. Application of a network of pyrometers in textile industry is the final goal.Fundação para a Ciência e a Tecnologia (FCT

Desenvolvimento e avaliação de um simulador de chuvas para teste acelerado de degradação

Entre os principais agentes de degradação em alvenarias externas e seus componentes, a chuva e o vento são considerados responsáveis por até 70% dos casos de infiltração, causando problemas que vão desde problemas estéticos a decomposição de elementos que constituem as fachadas. Apesar dos estudos de erosão se concentrarem na avaliação de blocos de terra, nos elementos a base de cimento Portland, a retirada do hidróxido de sódio livre por lixiviação, aumentando a porosidade, aumenta também a susceptibilidade ao ataque por sulfatos e a carbonatação e, por conseguinte, expõe os compostos cimentícios à decomposição. Por outro lado, o hidróxido de cálcio lixiviado reage com o gás carbônico presente no ar precipitando-se na superfície em forma de crostas brancas, reacção esta denominada de eflorescência. Apesar dos revestimentos protegerem as paredes de intempéries, os rebocos à base de cimento também estão passivos à ocorrência de eflorescência e, por conseguinte, de degradação pela acção de chuvas. Neste trabalho é feita uma breve revisão sobre os ensaios de simulação de chuvas já publicados e, em seguida, apresentada uma proposta de equipamento de ensaio, metodologia para levantamento de dados e validação do teste através da correlação dos parâmetros adoptados com os dados de caracterização de chuvas em Portugal

Synthesis and Characterization of Water Stable η3-Allyl Dicarbonyl Complexes of Molybdenum(II)

Trabalho apresentado nas VIII Jornadas CICECO, 18-19 de março 2011, Aveiro, PortugalN/

Enantiomeric separation of tramadol and Its metabolites: method validation and application to environmental samples

The accurate assessment of racemic pharmaceuticals requires enantioselective analytical methods. This study presents the development and validation of an enantioselective liquid chromatography with a fluorescence detection method for the concomitant quantification of the enantiomers of tramadol and their metabolites, N-desmethyltramadol and O-desmethyltramadol, in wastewater samples. Optimized conditions were achieved using a Lux Cellulose-4 column 150 × 4.6 mm, 3 µm isocratic elution, and 0.1% diethylamine in hexane and ethanol (96:4, v/v) at 0.7 mL min−1. The samples were extracted using 150 mg Oasis® mixed-mode cation exchange (MCX) cartridges. The method was validated using a synthetic effluent of a laboratory-scale aerobic granular sludge sequencing batch reactor. The method demonstrated to be selective, accurate, and linear (r2 > 0.99) over the range of 56 ng L−1 to 392 ng L−1. The detection and the quantification limits of each enantiomer were 8 ng L−1 and 28 ng L−1 for tramadol and N-desmethyltramadol, and 20 ng L−1 and 56 ng L−1 for O-desmethyltramadol. The feasibility of the method was demonstrated in a screening study in influent and effluent samples from a wastewater treatment plant. The results demonstrated the occurrence of tramadol enantiomers up to 325.1 ng L−1 and 357.9 ng L−1, in the effluent and influent samples, respectively. Both metabolites were detected in influents and effluentsinfo:eu-repo/semantics/publishedVersio