Analytical characterization of ancient mortars from the archaeological roman site of Pisões (Beja, Portugal)

The analytical characterization of mortar samples from the roman archaeological site of Pisões, located in Southern Portugal, were carried out by means of X-ray diffractometry (XRD), thermogravimetry (TGADTA), optical and electron scanning microscopy (SEM-EDS), potentiometry and combustion analysis. The Pisões archaeological complex includes a villa rustica, characterized by well-preserved mosaics and thermal baths, as well as a mill and a mausoleum. Countryside villae epitomized the Romanization of the Iberian Peninsula for over six centuries (2nd century BCE–4th century CE). Nevertheless, most of the Roman villae identified in Portugal have not yet been systematically explored and studied. This study provides valuable data on the construction materials and techniques used in Roman times in the Iberian Peninsula. The careful selection of raw materials and the use of natural and artificial pozzolanic materials can explain the favourable state of conservation, mechanical strength and long-term durability of these mortars

Implementação de um compressor JPEG em FPGA

Este documento descreve a implementação com pipeline de um compressor JPEG em FPGA. Para isso, apresenta-se a funcionalidade e implementação dos blocos principais da arquitectura do compressor. O destaque vai para a DCT 2-D, implementada com 2 blocos DCT 1-D e um buffer de transposição. O componente mais crítico em termos de espaço e desempenho é o multiplicador da DCT 1-D, que por ser usado para multiplicar um inteiro por uma de 4 constantes reais possui uma arquitectura baseada em 4 barrel shifters, e é aqui apresentado em maior detalhe

Pix2Pix-OnTheFly: Leveraging LLMs for Instruction-Guided Image Editing

The combination of language processing and image processing keeps attracting increased interest given recent impressive advances that leverage the combined strengths of both domains of research. Among these advances, the task of editing an image on the basis solely of a natural language instruction stands out as a most challenging endeavour. While recent approaches for this task resort, in one way or other, to some form of preliminary preparation, training or fine-tuning, this paper explores a novel approach: We propose a preparation-free method that permits instruction-guided image editing on the fly. This approach is organized along three steps properly orchestrated that resort to image captioning and DDIM inversion, followed by obtaining the edit direction embedding, followed by image editing proper. While dispensing with preliminary preparation, our approach demonstrates to be effective and competitive, outperforming recent, state of the art models for this task when evaluated on the MAGICBRUSH dataset

Psicoterapia Sim!: Eficácia, Efectividade e Psicoterapeutas (em Portugal)

O presente artigo resulta de uma conferência realizada na Livraria Barata, no âmbito dos “Encontros com a Psicologia,” organizados pela Associação Portuguesa de Psicologia. Os autores equacionam três temáticas, inevitavelmente articuladas: (1) eficácia geral e comparativa da psicoterapia; (2) efectividade da psicoterapia (em Portugal); e (3) características dos psicoterapeutas portugueses. Estas duas últimas temáticas tomam em consideração estudos empíricos realizados em Portugal

Evaluation of Pozzolanic Reactivity of Artificial Pozzolans

Materials Science Forum Vols. 730-732 (2013) pp 433-438Pozzolanicity is a very interesting issue regarding building materials, as a way to enhance mortars and concrete durability. This property results from the reaction between calcium hydroxide and silica and alumina based materials. Different types of natural and artificial pozzolans show pozzolanic activities that differ depending on the materials characteristics. Therefore, the study of this property, namely its reactivity with calcium hydroxide, reveals itself to be important in the selection of the type and content of these materials. This paper presents the results of several pozzolanic reactivity methods, applied to different pozzolanic materials. The selected pozzolanic methods include Chapelle method, Fratinni method and Strength Activity Index. Those tests have been applied to evaluate the reactivity of various kinds of artificial pozzolans. The correlation between the test methods are presented and discussed

Analytical and numerical modelling of damage and fracture of advanced composites

Tese de Doutoramento. Engenharia Mecânica. Faculdade de Engenharia. Universidade do Porto. 201

Earthen plasters based on illitic soils from Barrocal region of Algarve: contributions for building performance and sustainability

Clayish earth-based mortars can be considered eco-efficient products for indoor plastering since they can contribute to improve important aspects of building performance and sustainability. Apart from being products with low embodied energy when compared to other types of mortars used for interior plastering, mainly due to the use raw clay as natural binder, earth-based plasters may give a significant contribution for health and comfort of inhabitants. Due to high hygroscopicity of clay minerals, earth-based mortars present a high adsorption and desorption capacity, particularly when compared to other type of mortars for interior plastering. This capacity allows earth-based plasters to act as a moisture buffer, balancing the relative humidity of the indoor environment and, simultaneously, acting as a passive removal material, improving air quality. Therefore, earth-based plasters may also passively promote the energy efficiency of buildings, since they may contribute to decreasing the needs of mechanical ventilation and air conditioning. This study is part of an ongoing research regarding earth-based plasters and focuses on mortars specifically formulated with soils extracted from Portuguese ‘Barrocal’ region, in Algarve sedimentary basin. This region presents high potential for interior plastering due to regional geomorphology, that promote the occurrence of illitic soils characterized by a high adsorption capacity and low expansibility. More specifically, this study aims to assess how clayish earth and sand ratio of mortars formulation can influence the physical and mechanical properties of plasters. For this assessment four mortars were formulated with different volumetric proportions of clayish earth and siliceous sand. The results from the physical and mechanical characterization confirmed the significantly low linear shrinkage of all the four mortars, as well as their extraordinary adsorption-desorption capacity. These results presented a positive correlation with mortars´ clayish earth content and are consistent with the mineralogical analysis, that confirmed illite as the prevalent clay mineral in the clayish earth used for this study. Regarding mechanical resistance, although the promising results of the adhesion test, the flexural and compressive strength results suggest that the mechanical resistance of these mortars should be slightly improved. Considering the present results the mortars mechanical resistance improvement may be achieved through the formulation of mortars with higher clayish earth content, or alternatively, through the addition of natural fibers to mortars formulation, very common in this type of mortars. Both those options will be investigated in future research

Housing Policy in the Eurozone Countries: a Multidimensional Contribute to the Analysis of Socio-economic Factors (2010-2014)

The latest global economic and financial crisis translated in adverse social consequences on many aspects, including the income and social situation of households and their living conditions, especially when the housing phenomenon is addressed. This reality of uncertainty as made even more relevant the study of the housing phenomenon, in particular from a perspective of analysis of its evolution. In this context, we revisit EUROSTAT’s databases which contain general economic indicators, housing stock indicators, housing affordability indicators, population and social conditions indicators and housing quality indicators, for twelve Euro Area countries, during 5 years, with a multidimensional perspective, using the HJ -BIPLOT method developed by Galindo (1986).This methodological approach identified and categorized twelve Euro Zone sample countries in latent constructs of reduced dimensionality related to the housing policy problematic. The simultaneous factorial representation identified the most relevant variables to characterize these countries, their trajectories during the period in analysis, and the relations between variables, between countries, and between variables and countries. This approach also made it possible to identify the most significant factors contributing to the countries performances as population at risk of poverty, unemployment rate, overburden rate, share of housing cost in disposable income, tenant and owner with mortgage or loan and also to cluster these countries according to their (dis)similitude. This analysis can be useful for housing research, when studying multivariate data and also, by its visual nature, a potential tool for producing richer information not only for the academia but also for policy makers

Earth Plasters: The Influence of Clay Mineralogy in the Plasters’ Properties

Earth-based mortars have been used all over the world since ancient times in an extensive range of building types from vernacular architecture to monuments. Plastering is one of the most common contemporary applications of earth-based mortars used for earthen-building conservation or modern architecture. Raw earth is a very diverse natural material, and clay minerals play a key role in plaster properties being responsible for their setting process and providing the capacity of balancing the indoor hygrometric conditions of buildings. This capacity offers significant benefits to energy savings delivering comfort and health of inhabitants and also contributes to building conservation. For this study, three mortars were produced with different clayish earths to assess the influence of clay mineralogy. Mortars characterization confirmed that clay mineralogy drives important plaster properties, such as vapour adsorption and drying shrinkage, while also having a significant influence on mechanical strength, dry abrasion, and thermal conductivity. Within the studied mortars, illitic clayish earth stands outs as more adequate for earth-based plasters, showing balanced properties, namely linear drying shrinkage, mechanical strength, dry abrasion, and water vapour adsorption.authorsversioninpres