Archaeometallurgical study of the Proto-historic collection of Moinhos de Golas (North Portugal): a forecast for technological changes?

This work presents the archaeometallurgical study of a group of metallic artefacts found in Moinhos de Golas site, Vila Real (North of Portugal), that can generically be attributed to Proto-history (1st millennium BC, Late Bronze Age and Iron Age). The collection is composed by 35 objects: weapons, ornaments and tools, and others of difficult classification, as rings, bars and one small thin bent sheet. Some of the objects can typologically be attributed to Late Bronze Age, others are of more difficult specific attribution. The archaeometallurgical study involved x-ray digital radiography, elemental analysis by micro-energy dispersive X-ray fluorescence spectrometry and scanning electron microscopy with energy dispersive spectroscopy, microstructural observations by optical microscopy and scanning electron microscopy. The radiographic images revealed structural heterogeneities frequently related with the degradation of some artefacts and the elemental analysis showed that the majority of the artefacts was produced in a binary bronze alloy (Cu-Sn) (73%), being others produced in copper (15%) and three artefacts in brass (Cu-Zn(-Sn-Pb)). Among each type of alloy there’s certain variability in the composition and in the type of inclusions. The microstructural observations revealed that the majority of the artefacts suffered cycles of thermo-mechanical processing after casting. The diversity of metals/alloys identified was a discovery of great interest, specifically due to the presence of brasses. Their presence can be interpreted as importations related to the circulation of exogenous products during the Proto-history and/or to the deposition of materials during different moments at the site, from the transition of Late Bronze Age/Early Iron Age (Orientalizing period) onwards, as during the Roman period.

Characterization of earth-based mortars for rammed earth repair

All over the world, many earth buildings are deteriorating due to lack of maintenance and repair. Repairs on rammed earth walls are mainly done with mortars, by rendering application; however, often the repair is inadequate, resorting to the use of incompatible materials, including cement-based mortars. It has been observed that such interventions, in walls that until that day only had presented natural ageing issues, created new problems, much more dangerous for the building than the previous ones, causing serious deficiencies in this type of construction. One of the problems is that the detachment of the new cement-based mortar rendering only occurs after some time but, until that occurrence, degradations develop in the wall itself. When the render detaches, instead of needing only a new render, the surface has to be repaired in depth, with a repair mortar. Consequently, it has been stablished that the renders, and particularly repair mortars, should have physical, mechanical and chemical properties similar to those of the rammed earth walls. This article intends to contribute to a better knowledge of earth-based mortars used to repair the surface of rammed earth walls. The studied mortars are based on four types of earth: three of them were collected from non-deteriorated parts of walls of unstabilized rammed earth buildings located in Alentejo region, south of Portugal; the fourth is a commercial earth, consisting mainly of clay. Other components were also used, particularly: sand to control shrinkage; binders stabilizers such as dry hydrated air-lime, natural hydraulic lime, Portland cement and natural cement; as well as natural vegetal fibers (hemp fibers). The experimental analysis of the mortars in the fresh state consisted in determining the consistency by flow table and the bulk density. In the hardened state, the tests made it possible to evaluate the following properties: linear and volumetric shrinkage; capillary water absorption; drying capacity; dynamic modulus of elasticity; flexural and compressive strength.

The perfect paint in modern art conservation: a comparative study of 21st century vinyl emulsions

Contemporary painting places, and will continue to place, several questions about its meaning, its chemical nature, its durability and the best way to preserve it. This research aims at putting together comprehensive data on vinyl based paints, including their components, their properties, their aging behavior and their response to selected cleaning products. In this project degradation mechanisms of vinyl binders and formulations used in the 20th and 21st century were studied. Stability over time of selected vinyl polymers was assessed through natural indoor and artificially aging. The objective was to enhance knowledge and understanding of vinyl emulsion formulations and their performance over time. Overall conservation state of pictorial layers namely, adhesion, cohesion and discoloration of selected case studies from the Portuguese artist Julião Sarmento (b.1948) was correlated with the observed molecular level changes studied in laboratory experiments. Sarmento’s paintings were chosen due to conservation concerns (discoloration) on some of his works from the 90’s. Besides, research was carried out to start increasing the knowledge of what can be expected of PVAc based paints in terms of response to conservation treatments namely, surface cleaning. Artificial aging showed that the most recent formulations which are based on a poly(vinyl acetate), poly(vinyl chloride) and polyethylene terpolymer are less stable when compared to some homopolymer formulations. From the four pigments studied, titanium dioxide rutile and a carbon based black proved to be stabilizers for both types of polymer. The mixture lithopone plus calcium carbonate has showed to have a photocatalytic effect on the binders. The studied paintings showed to be in an overall good state of conservation except for the paintings created in the 90’s with white glue and a mixture of white lithoponeand calcium carbonate. Discoloration of this white paint seems to be irreversible and ongoing and is still a major concern. The disapearance of the plasticizer was the only change detected. The current works created by Sarmento are expected to be more stable as they were painted using the rutile titanium dioxide. Immersion/cleaning tests showed that vinyl based paints can be susceptible to water and organic solvents like ethanol as some evidences point to the removal/diffusion of additives from the paint. The observations made point to the need to further proceed in this research field.

Microinjection molding of polyamide 6/carbon nanotube composites

Microinjection molding of polymer composites with carbon nanotubes (CNT) requires previous production of the nanocomposites, often by melt extrusion. Each processing step has a thermo-mechanical effect on the polymer melt, conveying different properties to the final product. In this work, polyamide 6 and its composites with pristine and functionalized CNT (f-CNT) were processed by a mini twin-screw extrusion, followed by microinjection molding. The morphology induced on the polymer by each process was analyzed by differential scanning calorimetry and wide angle X-ray diffraction. Calorimetric analysis showed a secondary crystallization for the microinjected materials, absent for the extruded materials. The characterization of microinjected polyamide 6 by X-ray diffraction revealed a large contribution of the c phase to the total crystallinity, mainly in the skin region, while the nanocomposites and extruded materials were characterized by a larger contribution of the a phase. Functionalization of CNT did not affect significantly the polymer morphology compared to composites with pristine CNT.

Melhoria da eficiência energética em edifícios dos anos 70: implementação de soluções sustentáveis low-tech e low-cost

Dissertação de mestrado em Construção e Reabilitação Sustentáveis

Impact performance prediction of injection-molded talc-filled polypropylene through thermomechanical environment assessment

Due to the fact that different injection molding conditions tailor the mechanical response of the thermoplastic material, such effect must be considered earlier in the product development process. The existing approaches implemented in different commercial software solutions are very limited in their capabilities to estimate the influence of processing conditions on the mechanical properties. Thus, the accuracy of predictive simulations could be improved. In this study, we demonstrate how to establish straightforward processing-impact property relationships of talc-filled injection-molded polypropylene disc-shaped parts by assessing the thermomechanical environment (TME). To investigate the relationship between impact properties and the key operative variables (flow rate, melt and mold temperature, and holding pressure), the design of experiments approach was applied to systematically vary the TME of molded samples. The TME is characterized on computer flow simulation outputsanddefined bytwo thermomechanical indices (TMI): the cooling index (CI; associated to the core features) and the thermo-stress index (TSI; related to the skin features). The TMI methodology coupled to an integrated simulation program has been developed as a tool to predict the impact response. The dynamic impact properties (peak force, peak energy, and puncture energy) were evaluated using instrumented falling weight impact tests and were all found to be similarly affected by the imposed TME. The most important molding parameters affecting the impact properties were found to be the processing temperatures (melt andmold). CI revealed greater importance for the impact response than TSI. The developed integrative tool provided truthful predictions for the envisaged impact properties.

Adipogenic cell sheets to recreate in vitro adipose tissue microenvironments

Cell sheet (CS) engineering, taking advantage of cellular self-matrix organized as in native tissue, has been largely explored, including by us, for different purposes [1â 3]. Herein we propose for the ï¬ rst time, the use of human adipose stem cells (hASCs)-derived CS to create adipose tissue analogues with different levels of maturation. hASCs were cultured on UpCellTM thermo-responsive dishes for 1, 3 and 5 days under basal conditions previously established by us [3]. The inï¬ uence of pre-differentiation time and respective cell number, over CS stability and differentiation was assessed. Mechanically robust CS were only obtained with 5 days pre-differentiation period. Adipogenesis was followed along the culture assessing the variation of expression of mesenchymal (CD73, CD105 but not CD90) and adipogenic (PPARg, FABP4 and LPL) markers by ï¬ ow cytometry, immunocytochemistry and RT-PCR. Increased ratio of differentiated cells was achieved for longer pre-differentiation periods, while maturation degree was modulated by the maintenance medium. Independently of the overall CS differentiation/maturation level, 3D constructs were fabricated by stacking and further culturing 3 CS. Thus, by varying the culture conditions, different 3D adipose tissue-like microenvironments were recreated, enabling future development of new tissue engineering strategies, as well as further study of adipose tissue role in the regeneration of different tissues.

Estudo da ligação entre componentes estruturais de GFRP (glass fiber reinforced polymer) e componentes estruturais em betão

Dissertação de mestrado integrado em Engenharia Civil

Implementação de métodos para análise de produtos acabados e matérias-primas no laboratório da empresa TMG Automotive

Dissertação de mestrado em Técnicas de Caraterização e Análise Química

Development of an integrated approach to reliability management and operation

The research described in this thesis has been developed as a part of the Reliability and Field Data Management for Multi-component Products (REFIDAM) Project. This project was founded under the Applied Research Grants Scheme administered by Enterprise Ireland. The project was a partnership between Galway-Mayo Institute of Technology and Thermo King Europe. The project aimed to develop a system in order to manage the information required for reliability assessment and improvement of multi-component products, by establishing information flows within the company and information exchange with fleet users.

Development of a life cycle management system for remote products.

The research described in this thesis has been developed as a part of the Reliability and Field Data Management for Multi-Component Products (REFIDAM) Project. This project was funded under the Applied Research Grants Scheme administered by Enterprise Ireland. The project was a partnership between Galway-Mayo Institute of Technology and an industrial company, Thermo King Europe. The project aimed to develop a system to manage the information required for maintenance costing, cost of ownership, reliability assessment and improvement of multi-component products, by establishing information flows between the customer network and across the Thermo King organisation.

К проблеме термо-геодинамики Кавказа и природе возникновения черноморской и каспийской впадин

მძლავრი ვერტიკალური წანაცვლებები მანტიაში წარმოიქმნა, დანალექ ფენაში კი ის უმნიშვნელოა. იგულისხმება, რომ ოკეანე „ტეტისის“ გამეჩხერება დაკავშირებულია მანტიასა და ქერქში ვერტიკალურ თერმომონაცვლებათა პროცესთან. შესაძლოა, რომ უგრანიტო ფენის წარმოქმნა შავ ზღვაში და კასპიის ზღვის ღრმა ნაწილში ამ პერიოდში ამოზევებას და გადარეცხვას უკავშირდება. რღვევები მოხოს ზედაპირზე წარმოიქმნება, გრძელდება „ბაზალტში“, ინტენსიურად ვითარდება „გრანიტში“ და დღემდე არსებობს დანალექ ფენში, რაც რეგიონში თანამედროვე მიწისძვრებს განაპირობებს.

Constituição da alexina e mechanismo da hemolyse especifica

Os autores observam que após a inactivação de sôro de cobaya a 54° durante 30 minutos permanecem no sôro as fracções thermolabeis em quantidade apreciavel; um tal sôro conservado na temperatura de 6°, por espaço de 18 horas, regenera parte da sua actividade alexica perdida. 2° Confirma-se a existencia de 4 componentes do complemento. 3° O chamado terceiro componente de Ritz e Coca é na verdade constituidos por dois elementos, pelos menos, differentes: um destructivel pelo formol e outro destructivel pelo hydrosulphito de sodio. 4° A ammonia, o formol e o hydrosulpito de sodio são capazes de destruir os constituintes thermoresistentes da alexina do sôro inactivado a 56° 30 minutos, ao passo que as emulsões de levedos, de orgãos ou de gelose não o são. 5° As emulsões de levedo addicionadas a uma mistura em partes eguaes de sôro fresco de cobaya e de sôro aquecido a 56°, 30 m., são capazes de retirar não só o terceiro componente contido no sôro fresco da mistura, mas tambem o terceiro componente contido no sôro inactivado pelo calor. 6° Sem excluir a hypothese de uma floculação em que o sôro aquecido exerça o papel de um colloide protector, os autores admittem que a inactivação do complemento pelas emulsões de levedo ou pela gelose seja devida a substancias thermolabeis, do sôro, depois de adsorpção por essas emulsões, de substancias anti-tripticas. 7° Os diversos elementos que constituem a alexina são adsorvidos pelos globulos sensibilizados na seguinte ordem: Globulos-sensibilizadora-Fracção thermo-resistente sensivel á ammonia-Fracção thermolabil Globulina-Fracção thermolabil albumina-Fracção thermoresistente sensivel ao formol-Fracção thermoresistente sensivel ao hydrosulphito de sodio. 8° Na reacção de Bordet-Wassermann fortemente positiva é fixada sobretudo a fracção globulina thermolabil do complemento e não sómente o terceiro componente como seria licito esperar; a fracção thermolabil albumina permanece de regra livre e activa no liquido. 9° Os autores acham que se deve considerar como demonstrada a origem hepatica da alexina. Segundo experiencias procedidas em cães intoxicados pelo chloroformio não só baixa consideravelmente o titulo alexico global do sôro mas tambem os titulos, de todos os constituintes da alexina separadamente, soffrem, com a excepção da fracção thermolabil globulina, uma reducção muito accentuada.

O grupo pullorum-gallinarum em provas bacteriologicas comparativas

Foram examinadas 38 amostras de germens do grupo pullorumgallinarum, de origem européa, americana ou isoladas no Brasil, acompanhadas bacteriologicamente durante 3 annos, na fixidez de suas propriedades ou na possibilidade de sua transformação dum typo em outro. a) Distinguiram-se no estudo das propriedades cinco typos de germens no grupo pullorumgallinarum - 1) pullorum gazogeno, 2) pullorum não gazogeno, 3) intermedius, 4) gallinarum ou intermedius? gazogeno, 5) gallinarum não gazogeno. Os 2 primeiros e o 5º já bem cinhecidos e acceitos; o 4º admittido por Beck & Eber, em 1929, o 3º evidenciado por nós em 1935. b) O typo gallinarum gazogeno deve ser mais propriamente talvez considerado como typo intermedius gazogeno a vista de sua acção sobre sorbita e a xylose e sobre o meio de Jordan. c) O quadro final resume as caracteristicas mais importantes destes cinco typos, baseando-se a differenciação principalmente na alteração do vermelho neutro, na produção de H²S, na fermentação de glycerina, rhamnose, xylose, dulcita, sorbita e maltose, na acção sobre o tartaro, na producção de gaz e no aspecto das colonias na superficie de certos meios de cultura. d) Outras propriedades biologicas examinadas - acção sobre o leite, sôro de leite, dextrina, etc, admitidos por varios pesquizadores na differenciação, parecem distituidas de valor. e) As amostras mantiveram fixas as suas propriedades durante todo o tempo em que foram acompanhadas. A hypothese de uma possivel transformação de um typo em outro não foi confirmada em nenhuma das amostras estudadas, justificando a entidade dos varios typos admittidos. f) Discrepancias observadas na fermentação da maltose, referidas por varios pesquizadores com germens desse grupo, não foram confirmadas no presente trabalho. g) Encontrou-se no sôro sanguineo um factor capaz de transformar a maltose em glycose, tornando aquelle assucar fermentescivel. Essa substancia é thermo-estavel e resiste á acção de substancias antidiastasicas. h) A analyse sôrologica das amostras estudadas não permittiu differenciar os typos entre si.

Joint estimates of automatic and discretionary fiscal policy for the OECD

Official calculations of automatic stabilizers are seriously flawed since they rest on the assumption that the only element of social spending that reacts automatically to the cycle is unemployment compensation. This puts into question many estimates of discretionary fiscal policy. In response, we propose a simultaneous estimate of automatic and discretionary fiscal policy. This leads us, quite naturally, to a tripartite decomposition of the budget balance between revenues, social spending and other spending as a bare minimum. Our headline results for a panel of 20 OECD countries in 1981-2003 are .59 automatic stabilization in percentage-points of primary surplus balances. All of this stabilization remains following discretionary responses during contractions, but arguably only about 3/5 of it remains so in expansions while discretionary behavior cancels the rest. We pay a lot of attention to the impact of the Maastricht Treaty and the SGP on the EU members of our sample and to real time data.