Past expectations as a determinant of equilibrium prices - hysteresis in a simple economy

We give an illustration of hysteresis (path-dependence) in a simple economy. In the presence of multiple possible equilibrium prices, we find that past expectations determine present prices. This phenomenon of path-dependence is robust under perturbations of the economy.Hysteresis, Path-dependence, Tatônnement, Equilibrium selection

A third sector in the core-periphery model: non-tradable goods

We extend an analytically solvable core-periphery model by introducing a monopolistically competitive sector of non-tradable goods. We study how trade costs affect the spatial distribution of economic activity. Trade costs have no effect when the elasticity of substitution among non-tradable goods is low. In this case, concentration of all production (of tradable and non-tradable goods) is the unique equilibrium. When the elasticity of substitution among non-tradable goods is high, we find two equilibrium configurations: symmetric dispersion of the production of tradable and non-tradable goods, if trade costs are high; and concentration of production of tradable goods with asymmetric dispersion of production of non-tradable goods, if trade costs are low.New economic geography, Core-periphery model, Footloose entrepreneur, Nontradable goods

The core periphery model with asymmetric inter-regional and intra-regional trade costs

We generalize the model of Krugman (1991) to allow for asymmetric trade costs between regions and for (asymmetric) trade costs that are internal to the regions. We find that industrial activity, in a region, is enhanced by higher costs of importing and lower costs of exporting (more precisely, by a higher ratio between the two trade costs). This suggests that countries may impose tariffs on imported goods and seek to remove the import tariffs in other countries (unilateral protectionism) in order to foster industrial activity. Industrial activity is also promoted by lower domestic internal trade costs and higher foreign internal trade costs (more precisely, by a lower ratio between the two trade costs).New Economic Geography, Core-Periphery, Trade costs, Unilateral protectionism.

O corpo humano no ensino da escultura em Portugal:mimese e representação

Tese de doutoramento, Belas-Artes (Escultura), 2010, Universidade de Lisboa, Faculdade de Belas-ArtesDisponível no document

Five really easy steps to build a homemade low-cost simulator

Published online march 2012Aim. The aim of this study was to evaluate how simple it is to build a homemade low-cost simulator using a simple 5-step scheme. Methods. A scheme explaining how to build an endoscopic surgery simulator in 5 easy steps was presented to 26 surgeons. The simulator required a pair of scissors and easy-to-find materials. Its total cost was less than €35. The participants assessed the simulator using common endoscopic training toys or ex vivo tissue and completed an anonymous query comparing it with other commercial simulators that they had experienced before. Results. In all, 84.6% found the simulator really easy to build. Every participant felt that he or she could do the same simulator themselves. Comparing with other commercial available box simulators, the majority of participants found the homemade simulator easier to (a) mount and dismount, (b) transport, (c) clean, and (d) use when practicing alone. Conclusions. Anyone can build its own simulator for a small amount of money.The author(s) received no financial support for the research, authorship, and/or publication of this article

Evaluation of the gas emissions during the thermochemical conversion of eucalyptus woodchips

The combustion of solid biomass in industrial boilers involves a sequence of processes that include heating, drying, devolatilization, and char conversion. To maintain a repeatable and fully controlled environment, and to monitor all the dynamics involved in the phenomena at a real scale, field-scale experiments become necessary to perform investigations. In this way, to evaluate different thermochemical conversion conditions of biomass particles under an oxidative atmosphere, and to quantify the emission of the main gas compounds continuously, a small-scale reactor was developed and presented in this paper. Hence, in this work, larger particles of eucalyptus are burned at 400 and 800 °C under different stoichiometric conditions to understand the differences between different biomass conversion regimes (gasification and combustion). The analysis of the mass loss at the different temperatures was characterized by only two different and consecutive stages for both thermochemical conditions. The first region does not present the influence on the air flow rate; however, there is a significant difference in the second region. This fact highlighted the importance of the diffusion of oxygen during the char conversion. Regarding the quantification of the gas compounds, an increase of around 3 times in the CO and CO2 emissions when gasification occurs was observed at 400 °C. However, at 800 °C, the same trend was verified, also verifying a considerable amount of CH4.Portuguese Foundation for Science and Technology (FCT) within the R&D Units Project Scope UIDB/00319/2020 (ALGORITMI), and R&D Units Project Scope UIDP/04077/2020 (MEtRICs

Role of Content Analysis in Improving the Curation of Experimental Data

As researchers are increasingly seeking tools and specialized support to perform research data management activities, the collaboration with data curators can be fruitful. Yet, establishing a timely collaboration between researchers and data curators, grounded in sound communication, is often demanding. In this paper we propose manual content analysis as an approach to streamline the data curator workflow. With content analysis curators can obtain domain-specific concepts used to describe experimental configurations in scientific publications, to make it easier for researchers to understand the notion of metadata and for the development of metadata tools. We present three case studies from experimental domains, one related to sustainable chemistry, one to photovoltaic generation and another to nanoparticle synthesis. The curator started by performing content analysis in research publications, proceeded to create a metadata template based on the extracted concepts, and then interacted with researchers. The approach was validated by the researchers with a high rate of accepted concepts, 84 per cent. Researchers also provide feedback on how to improve some proposed descriptors. Content analysis has the potential to be a practical, proactive task, which can be extended to multiple experimental domains and bridge the communication gap between curators and researchers. [This paper is a conference pre-print presented at IDCC 2020 after lightweight peer review.

Webquests : um instrumento didáctico inovador

A comunicação, o trabalho em equipa, a resolução de problemas e as capacidades críticas e criativas são cada vez mais importantes na sociedade da informação. Por esse motivo, o construtivismo tem tomado um papel cada vez mais relevante no ensino, que privilegia agora as capacidades e os processos mentais dos alunos e não tanto a memória.Os webquests apresentam uma boa solução de apoio a este método de ensino: requerem esforços de procura, análise e síntese, desenvolvendo processos cognitivos simultâneos à aquisição de conhecimento. Por outro lado, a sua relevância reside também no facto de ser construído e talhado especialmente para cobrir áreas curriculares relativamente às quais os professores geralmente sentem lacunas em termos de material didáctico auxiliar.Neste artigo pretende-se demonstrar as potencialidades desta ferramenta, quer no ensino presencial quer no ensino à distância