Hedonic Prices Indexes for New Passenger Cars in Portugal (1997- 2001)

This paper evaluates the effects of quality change on the price index for new passenger cars in Portugal for the years 1997-2001. Hedonic regression models are studied, giving particular emphasis to the relation between the form of the price index and the specification of the hedonic equation and estimation method used. It is argued that when log-linear hedonic functions are used the effects of quality change should be evaluated using a method akin to the Oaxaca decomposition (Oaxaca R., 1973, "Male-Female Wage Differentials in Urban Labor Markets", International Economic Review, 14, 693-709), rather than using the traditional dummy variables method. The results of the empirical part of the paper indicate that the CPI component corresponding to the sales of new passenger cars may have been overestimated by as much as 2.2 percentage points per year. This corresponds to an overestimation of the overall CPI by about 0.15 percentage points per year. As a by- product of this analysis it is also possible to conclude that the quality of new cars sold in Portugal increased on average 4.8 percent per year during this period.CPI bias; Heteroskedasticity; Oaxaca decomposition.

Synthèse et modélisation de polyfullèrenes

The work developed during this thesis include the design, modeling, synthesis and characterization of new polymeric materials based on fullerenes for application in organic photovoltaics as morphology stabilizers. In view of such use, these materials have to present particular properties, among which a good solubility in organic solvents, a good miscibility with the light-absorber polymer as well as a morphological stability superior to those currently used materials, such as (bis-)PC60BM and the derivatives of indene-C60. Six different synthetic routes were studied and the electronic properties (LUMO orbital energy, electroaffinity, electrophilicity, reorganization energy, transfer integral and electron mobility) were determined by molecular modeling. Among these routes, the one called ''ATRAP'', not much studied in the literature yet, was finally retained. The physicochemical properties of the so-synthesized materials, grafted with different lateral chains, were determined by different characterization techniques and their application in thin films for Organic Photovoltaic devices was performed. When used as additives, these materials display a potential of stabilizing the P3HT/PC60BM layer, and this does not influence the performance of the device. After a thermal treatment, the observed behavior was the opposite of the expected, it means that a destabilization of the active layer was noted instead of a stabilization and the underlying mechanism was also studied by several experimental techniques. Finally, a depolymerization mechanism induced by light and/or heat was proposed. Within this process, the cleavage of the monomer-fullerene bond is responsible for creating defects, such as the depolymerization, cross-linkings or irreversible rearrangement of the thin layer. This cleavage can be either thermally activated or induced by the triplet state of the monomer, which also destabilizes this bond. Beyond that, this work also interested in: (i) the stabilization of the organic-inorganic interface within photovoltaic devices by tailoring organic groups able to bind to the inorganic surface, (ii) the stabilization of the lateral chain of conjugated polymers by the insertion of alkoxy chains, as well as (iii) the relation between the curvature of a carbon-based molecule and its reactivity to molecular oxygen. These studies, performed in parallel, drove to the proposition of new donor-acceptor hybrid materials based on hexabenzocoronene, which are capable of stacking over itself to form supramolecular structures similar to discotic liquid crystals. From the conclusions of this document, two novel materials were proposed, which electronic properties reveal that it is possible to design new materials that may be stable and efficient at the same time for application in organic photovoltaics.Die vorliegende Arbeit beinhaltet sowohl das Design und die Modellierung von neuartigen Fulleren-basierten Polymeren als auch deren Sythese und Charakterisierung. Für die Anwendung in photovoltaischen Zellen müssen diese Materialien spezielle Eigenschaften aufweisen, unter anderem eine gute Löslichkeit in organischen Lösungsmitteln, eine gute Mischbarkeit mit dem Licht-absorbienden Polymer sowie eineerhöhte morphologische Stabilität im Vergleich zu derzeit verwendeten Materialien, wie beispielsweise (bis-)PC60BM oder Derivaten von indene-C60. Sechs verschiedene Syntheserouten wurden angewandt. Elektronische Eigenschaften (LUMO Energie, Elekronenaffinität, Elektrophilie, Reorganisationsenergie, Transferintergrale und Elektronbeweglichkeit) wurden durch ''molecular modeling'' bestimmt. Als Sytheseweg erwies sich ein bisher aus der Literatur bekannter Weg (''ATRAP'') als erfolgreich. Die physikalisch-chemischen Eigenschaften der synthetisierten Materialien, welche sich durch verschiedene Seitenketten unterscheiden, wurden durch verschiedene Methoden charakterisiert. Die Anwendung in dünnen Filmen für Organische Photovoltaik wurde getestet. Wenn diese Materialien als sogenannte Additive in P3HT/PC60BM Schichten verwendet werden, stabilisieren sie die Morphologie während die Performance nahezu unverändert bleibt. Eine Wärmebehandlung führte überraschenderweise zu einer Destabilisierung der aktiven Schicht. Dieser Mechanismus wurde mit mehreren experimentellen Techniken studiert. Es wurde ein Mechanismus für eine Depolymerisation Licht bzw. Hitze vorgeschlagen. In diesem Prozesses ist die Spaltung der Monomer-Fulleren Bindung für die Bildung von Defekten durch Depolymerization, cross-linking oder irreversible Neuordnung der dünnen Schicht verantwortlich. Diese Spaltung kann thermisch entweder aktiviert werden oder aber durch Besetzung des Triplett-Zustandes des Monomers hervorgerufen werden, welcher auch diese Bindung destabilisieren kann. Darüber hinaus beschäftigt sich diese Arbeit mit (i) der Stabilisierung der organisch-anorganischen Grenzflächen inphotovolaischen Bauelementen (ii) der Stabilisierung der Seitenketten von konjugierten Polymeren, sowie mit (iii) dem Zusammenhang zwischen der Struktur von Kohlenstoff-basierten Molekülen und der Reaktivität gegenüber molekularem Sauerstoff. Auf Grundlage dieser parallel durchgeführten Studienwerden neuartige, Hexabenzocoronene basierte Donor-Akzeptor Hybrid-Materialien vorgeschlagen, welche supramolekulare Strukturen (Stapel) bilden, ähnlich wie diskotische Flüssigkristalle. Als Ergebniswerden zwei Materialien vorgeschlagen, die sowohl eine erhöhte Stabilität zeigen als auch eine bessere Effizienz in organischen photovoltaischen Bauelementen.Les travaux développés au cours de cette thèse comprennent le design, la modélisation, la synthèse et la caractérisation de nouveaux matériaux polymérisés à base de fullerène. Dans l'optique d'une utilisation au sein de cellules photovoltaïques, ces matériaux doivent présenter des propriétés particulières, parmi lesquelles une bonne solubilité dans les solvants organiques, une bonne miscibilité avec le polymère absorbeur de lumière ainsi qu'une stabilité morphologique supérieure à celles rencontrées pour les matériaux actuellement utilisés, tels les (bis-)PC60BM et les dérivés d'indène-C60. Six voies de synthèse ont été étudiées et les propriétés électroniques (énergie de l'orbitale LUMO, électroaffinité, électrophilicité, énergie de réorganisation, intégrale de transfert et mobilité électronique) qui en résultent ont été déterminées au moyen de la modélisation numérique. Parmi ces voies de synthèse, le chemin dit «ATRAP», peu étudié dans la littérature, a été finalement retenu. Les propriétés physico-chimiques de ces composés, greffés de différentes chaînes latérales, ont été déterminées au moyen de diverses techniques de caractérisation et leur application dans des couches minces au sein de dispositifs photovoltaïques a été mise en oeuvre. Utilisés en tant qu'additifs, ces matériaux révèlent un potentiel de stabilisation de la couche de P3HT/PC60BM, cette propriété n'affectant pas, pour autant, les performances de la cellule. Le comportement de ces couches après soumission à un traitement thermique a montré, à l’inverse, un phénomène de déstabilisation dont le mécanisme a été, lui aussi, étudié par diverses techniques expérimentales. Finalement, un mécanisme de dépolymérisation, induit par la lumière et/ou par la chaleur, a été proposé. Dans ce processus, la rupture de la liaison chimique entre le monomère et le fullerène est responsable de la création des défauts, comme de la dépolymérisation, des phénomènes de cross-linking ou du réarrangement irréversible de la couche mince. Cette rupture peut être soit thermiquement activée, soit induite par l'état triplet du monomère, qui déstabilise la liaison. Outre l'étude de ces composés, le présent travail s'est également intéressé (i) à la stabilisation de l'interface organique-inorganique au sein des dispositifs photovoltaïques, (ii) à la stabilisation de la chaîne latérale des polymères conjugués, ainsi que (iii) à la relation entre la géométrie de la molécule et sa réactivité avec l’oxygène moléculaire. Ces études, menées en parallèle, nous ont conduit à proposer de nouveaux matériaux hybrides du type donneur-accepteur, dérivés de l'hexabenzocoronène et capables de s'empiler pour former des structures similaires à des cristaux liquides discotiques. Partant de l'ensemble des conclusions tirées de ces travaux de thèse, deux composés ont été proposés, dont les propriétés électroniques révèlent qu'il est possible de dessiner des matériaux à la fois stables et efficaces pour une utilisation dans le domaine du photovoltaïque organique

Relatório de estágio - Arbitrare

The report in cause is related to the description and development of the activities during the internship made at ARBITRARE - the Arbitration center for the industrial property, domain names and corporate names. The first stage of the report consists in the description of the center services and its specificities, it will also be exalted the advantages of using this arbitration center. In the second stage of the internship, I will develop some theoretical aspects related to the areas of competence of ARBITRARE: industrial property, domain names and corporate name, It will also contain some practical aspects regarding the activities that we´re made during the internship, namely: the answers to the information requests asked by the ARBITRARE users. Finally, in the third stage of the internship I will write about a theoretical theme regarding the possibility of the silence could have the value of consent at the arbitration agreement in the Portuguese law. The reason why I’ve choose this theme is related with the problems that result from the lack of answer from the existing affected parties when they are solicited to participate at the procedure, in matter of fact, during the activity’s that I’ve developed during the internship, more specifically, the reading of the legislation regarding the disputes submitted to voluntary arbitration at ARBITRARE and also the research already done related with this issue by Dra. Joana Borralho Gouveia and Dra. Susana Condesso Diogo, I’ve noticed that even when the existing effected parties were notified to pronounce about the acceptance or not of the arbitration agreement, the existed affected parties choose to not say a word and the consequence of this behaviour is the archiving of the process according with article seven number tree of the legislation regarding the disputes submitted to voluntary arbitration at ARBITRARE. One proposal that could be the solution for this problem that is defended by some doctrine consists in a legislative amendment that would gave to silence the value of consent in the case of the existing affected parties choose to not say any word when they are confronted with the notification to participate at the arbitral procedure. My analysis will be related with the motives that explain why silence cannot have the value of declaration of negotiation according the law and if it is possible a legislative amendment in consideration of the mentioned purposes.O relatório em causa diz respeito à descrição e aprofundamento das actividades desenvolvidas durante o estágio no ARBITRARE – Centro de arbitragem para a propriedade industrial, nomes de domínio, firmas e denominações. A primeira fase do relatório vai consistir na descrição dos serviços e especificidades deste centro de arbitragem, enaltecendo também quais as vantagens da utilização do mesmo. Na segunda fase do relatório, irei desenvolver um resumo relativo às actividades desenvolvidas ao longo do estágio dando maior enfâse aos pedidos de informação e alguns aspectos teóricos relativamente às respectivas áreas de competência do ARBITRARE: propriedade industrial, nomes de domínio, firmas e denominações. Finalmente, na terceira fase do relatório, irei desenvolver um tema teórico relativamente às razões pelas quais o silêncio não pode valer como manifestação de consentimento na convenção de arbitragem no direito Português. A razão da escolha deste tema prende-se com a constatação dos problemas que surgem pela ausência de resposta por parte dos contrainteressados quando solicitados para participar no processo, de facto, ao longo das actividades que fui desenvolvendo ao longo de estágio, mais concretamente, na leitura do regulamento do ARBITRARE relativo aos litígios submetidos à arbitragem voluntária e também pela investigação já efectuada por parte da Dra. Joana Borralho Gouveia e Dra. Susana Condesso Diogo relativamente a esta problemática, tomei conhecimento que mesmo que devidamente notificados para se pronunciarem sobre a aceitação ou não do compromisso arbitral, os contraintessados optam por nada dizer sendo que a consequência decorrente da ausência de resposta se consubstancia no arquivamento do processo de acordo com o artigo 7º nº 3 do Regulamento do ARBITRARE para os litígios submetidos à arbitragem voluntária. Uma proposta que visa a solução deste problema, conforme defende alguma doutrina, poderia passar por uma alteração legislativa em que o silêncio valeria como declaração negocial de aceitação no caso de os contrainteressados optarem por não se manifestarem quando confrontados com a notificação para a participação no processo arbitral. A minha análise incidirá sobre os motivos pelos quais o silêncio não poderá valer como declaração negocial nestes casos tendo em conta o direito constituído e se é possível uma alteração legislativa tendo em conta as finalidades supramencionadas

Doing precolonial african history in postcolonial times: a roundtable

O objetivo deste artigo é o de promover uma discussão de cunho historiográfico sobre o lugar de África nas histórias atlântica e imperial. O debate gira em torno de um conjunto de questões: como colocar a África num lugar mais central da investigação histórica? Como cruzar a historiografia dedicada ao continente africano com aquela que trata das diásporas africanas? Qual tem sido a contribuição da historiografia portuguesa para o estudo da África pré-colonial? Qual é o significado e a utilidade da "África lusófona" como conceito e como campo de estudos? Qual o futuro da investigação sobre a África pré-colonial em termos de dificuldades, oportunidades e prioridades? Os três historiadores convidados para esta mesa-redonda não apresentam respostas definitivas para estas questões, mas abrem caminho para uma reflexão mais aprofundada.This debate article aims to promote a historiographical discussion on the place of Africa in Atlantic and imperial history. The debate revolves around a set of questions: how to bring Africa to the centre of historical research? How close or how distant is the historiography that focuses on the African continent and the one that deals with the African diasporas? What has been the contribution of Portuguese scholarship to the study of precolonial African history? What is the meaning and usefulness of "Lusophone Africa" as a concept and as a field of study? What future for research on precolonial Africa in terms of constraints, opportunities, and priorities? The three historians invited to this roundtable do not provide definitive answers to these questions, but they open the way for a deeper reflection

From Liberal Acceptance to Intolerance: Discourses on Sexual Diversity in Schools by Portuguese Young People

Purpose: This article explores different strands of educational discourse about sexual diversity in Portuguese schools, from the students’ perspectives.Method: The methodological approach consisted in conducting focus groups discussions: 36 with 232 young students (H = 106, M = 126) in 12 public secondary schools.Findings: Students reveal a polyphony of discourses that gravitate between liberal acceptance, conditional acceptance and intolerance.Research implications: Attention is drawn not only to discriminatory processes that question school as a democratic place for LGBT youth, but also to the gap between what is legally decreed and a lack of know-how in the approach to sexual diversity in school

Growth performance, biochemical composition and sedimentation velocity of Tetraselmis sp. CTP4 under different salinities using low-cost lab- and pilot-scale systems

Biomass harvesting is one of the most expensive steps of the whole microalgal production pipeline. Therefore, the present work aimed to understand the effect of salinity on the growth performance, biochemical composition and sedimentation velocity of Tetraselmis sp. CTP4, in order to establish an effective low-cost pilot-scale harvesting system for this strain. At lab scale, similar growth performance was obtained in cultures grown at salinities of 5, 10 and 20 g L-1 NaCl. In addition, identical settling velocities (2.4-3.6 cm h-1) were observed on all salinities under study, regardless of the growth stage. However, higher salinities (20 g L-1) promoted a significant increase in lipid contents in this strain compared to when this microalga was cultivated at 5 or 10 g L-1 NaCl. At pilot-scale, cultures were cultivated semi-continuously in 2.5-m3 tubular photobioreactors, fed every four days, and stored in a 1-m3 harvesting tank. Upon a 24-hour settling step, natural sedimentation of the microalgal cells resulted in the removal of 93% of the culture medium in the form of a clear liquid containing only vestigial amounts of biomass (0.07 ± 0.02 g L-1 dry weight; DW). The remaining culture was recovered as a highly concentrated culture (19.53 ± 4.83 g L-1 DW) and wet microalgal paste (272.7 ± 18.5 g L-1 DW). Overall, this method provided an effective recovery of 97% of the total biomass, decreasing significantly the harvesting costs.Agência financiadora Portuguese national budget P2020 Foundation for Science and Technology (FCT) CMAR/Multi/04326/2013 ALGARED+ 1398 EP - INTERREG V-A Espana Portugal project ALGACO2 project 023310 COST Action 1408 - European Network for Bio-products FCT SFRH/BD/105541/2014info:eu-repo/semantics/publishedVersio

Perturbação do comportamento alimentar - um diagnóstico de exclusão

In adolescents with weight loss, diagnoses other than eating disorders should be considered, namely neurological diseases. A 16-year-old girl with an intellectual development disorder was referred to the Adolescent Medicine outpatient clinic from Child Psychiatry with a diagnosis of eating disorder and persistent anemia. Her body mass index was consistently below the fifth percentile and long-lasting eating difficulties were reported since the age of 15. The girl had no other gastrointestinal, articular, or respiratory complaints, neither polyuria, polydipsia, or recurrent fever. Parental divorce and domestic violence were reported. The patient complained of excessive daytime sleepiness, asthenia, intermittent myalgia, and muscular weakness episodes. Phenotypic characteristics and personal medical history led to clinical suspicion of a neuromuscular disease and genetic study confirmed myotonic dystrophy type 1. This case highlights the importance of considering other diagnoses besides eating disorders in adolescents with eating problems. An exhaustive evaluation of personal and family medical history, patient complaints, and detailed physical examination is mandatory.info:eu-repo/semantics/publishedVersio

The use of cyclic triaxial tests in the characterization of portuguese UGM

Coarse aggregate is widely used in the unbound granular layers (UGM) of roads, in particular as granular sub-base and base. However, although various studies have been conducted on these materials, their mechanical behaviour still has not been properly characterized, in Portuguese conditions, especially due to reasons connected to the heterogeneity of the rock masses from which they come from. This has special importance for Portuguese pavement technology. In the attempt of contributing for a better knowledge of that behaviour, a work was developed having the aim of obtain the mechanical characterization and the establishment of behaviour models for crushed materials coming from different lithologies, namely limestone and granite, susceptible of being used as UGM. This paper describes the principal results obtained from the work and pointing out the main directives that can be extracted from it, in terms of the global behaviour of a road pavement