Rehabilitation of an important cultural and architectural heritage: the traditional adobe constructions in Aveiro district

Adobe is a low-cost construction material, locally available, presents excellent thermal and acoustic properties, and is associated to quite simple construction methods that only require a small consumption of energy. It is indeed an economically viable material, and its use respects the environmental equilibrium. Rehabilitation and strengthening of existing traditional adobe constructions contribute to the quality of life improvement of those who use them and for an increase of associated safety levels, particularly if an effective seismic strengthening is assured. The preservation of these constructions also contributes for the recognition of the advantages that adobe, as a structural material, presents, encouraging its use in new constructions, and allowing for the reduction of the efforts and resources that are affected to new edifications that normally replace the adobe existing ones. A research group at the University of Aveiro has been developing work aimed at the characterization of the vast traditional adobe constructed park of Aveiro district, which constitutes an important architectonic and cultural heritage. Studies on the composition and mechanical behaviour of adobe units and mortars, and on the structural behaviour of adobe masonry walls were conducted. These studies aim to establish a basis of knowledge that can support the interpretation of structural pathologies, calibration of numerical models, structural safety assessment, and design of strengthening solutions. This article presents and discusses the developed work, explaining how it can contribute for a more conscious development of rehabilitation practices

Dynamics of a Generalized Cosmological Scalar-Tensor Theory

A generalized scalar-tensor theory is investigated whose cosmological term depends on both a scalar field and its time derivative. A correspondence with solutions of five-dimensional Space-Time-Matter theory is noted. Analytic solutions are found for the scale factor, scalar field and cosmological term. Models with free parameters of order unity are consistent with recent observational data and could be relevant to both the dark-matter and cosmological-"constant" problems.Comment: 13 page

Zinc abundances in Galactic bulge field red giants: implications for DLA systems

Zinc in stars is an important reference element because it is a proxy to Fe in studies of damped Lyman-alpha systems, permitting a comparison of chemical evolution histories of bulge stellar populations and DLAs. In terms of nucleosynthesis, it behaves as an alpha element because it is enhanced in metal-poor stars. The aim of this work is to derive the iron-peak element Zn abundances in 56 bulge giants from high resolution spectra. These results are compared with data from other bulge samples, as well as from disk and halo stars, and damped Lyman-alpha systems, in order to better understand the chemical evolution in these environments. High-resolution spectra were obtained using FLAMES+UVES on the Very Large Telescope. We find [Zn/Fe]=+0.24+-0.02 in the range -1.3 < [Fe/H] < -0.5 and [Zn/Fe]=+0.06+-0.02 in the range -0.5 < [Fe/H] -0.1, it shows a spread of -0.60 < [Zn/Fe] < +0.15, with most of these stars having low [Zn/Fe]<0.0. These low zinc abundances at the high metallicity end of the bulge define a decreasing trend in [Zn/Fe] with increasing metallicities. A comparison with Zn abundances in DLA systems is presented, where a dust-depletion correction was applied for both Zn and Fe. Finally, we present a chemical evolution model of Zn enrichment in massive spheroids, representing a typical classical bulge.Comment: Accepted in Astronomy & Astrophysics, in press Date of acceptance: 13/05/2015. 19 pages, 14 Figs in Astronomy & Astrophysics, 201

Levantamento e caracterização do parque edificado em adobe na cidade de Aveiro

Até meados do século XX, o adobe foi um material de construção muito utilizado no distrito de Aveiro, em Portugal. Actualmente, nesta região, e em particular na cidade de Aveiro, permanecem ainda muitos exemplos de edifícios construídos em adobe, alguns de importante valor patrimonial e arquitectónico. No entanto, muitos destes edifícios têm sido votados ao abandono nas últimas décadas, especialmente pela escassez de conhecimento técnico para suporte à sua reabilitação e reforço. Reconhecendo-se esta necessidade de conhecimento, nos últimos anos começou a desenvolver-se trabalho de investigação nesse sentido. Neste artigo apresenta-se um trabalho de levantamento desenvolvido com o objectivo de caracterizar a distribuição e as características principais da edificação em adobe existente na cidade de Aveiro. Descreve-se, de forma sucinta, a metodologia adoptada, bem como os resultados obtidos. O conhecimento adquirido permitirá uma posterior selecção de edifícios representativos, para uma caracterização detalhada dos sistemas construtivos e das patologias mais comuns.Até meados do século XX, o adobe foi um material de construção muito utilizado no distrito de Aveiro, em Portugal. Actualmente, nesta região, e em particular na cidade de Aveiro, permanecem ainda muitos exemplos de edifícios construídos em adobe, alguns de importante valor patrimonial e arquitectónico. No entanto, muitos destes edifícios têm sido votados ao abandono nas últimas décadas, especialmente pela escassez de conhecimento técnico para suporte à sua reabilitação e reforço. Reconhecendo-se esta necessidade de conhecimento, nos últimos anos começou a desenvolver-se trabalho de investigação nesse sentido. Neste artigo apresenta-se um trabalho de levantamento desenvolvido com o objectivo de caracterizar a distribuição e as características principais da edificação em adobe existente na cidade de Aveiro. Descreve-se, de forma sucinta, a metodologia adoptada, bem como os resultados obtidos. O conhecimento adquirido permitirá uma posterior selecção de edifícios representativos, para uma caracterização detalhada dos sistemas construtivos e das patologias mais comuns

Outputs from the research developed at the University of Aveiro regarding the mechanical characterization of existing adobe constructions in Portugal and proposals for rehabilitation and strengthening

In Portugal, mainly in Aveiro region, adobe buildings were the prevailing construction system during the first half of the 20th century. Presently, the legacy that results from the patrimony built in that period is still significant-about 30% of the existing constructions in the region- and, moreover, it is comprised by a large number of patrimonial buildings of high historical, cultural and architectural value. A marked negligence in the rehabilitation of this patrimony has been observed in the last decades, and has resulted in the actual damage state presented by many of these constructions, which generally resulted in unfavourable safety and durability conditions. However, in the last years, an increasing interest in the conservation and rehabilitation of the adobe patrimony in the region, associated with environmental, economical and patrimonial safeguard factors, has been demonstrated by public administrative entities and also by the private sphere. In face of this reality, which emphasizes the need and importance of developing intervention strategies that may enable, by rehabilitation and/or strengthening, extending the lifespan of these structures, a group of researchers of the University of Aveiro has been developing a multidisciplinary study on the adobe construction in Portugal. The main objective of this research work is the creation of a test results database that may support rehabilitation and/or strengthening interventions, and also the study of solutions for the improvement of the structural behaviour of these constructions. In this sense, the research carried out was constituted seeking to contribute to the knowledge of this type of adobe masonry, focused mainly on their rehabilitation, providing information to the professionals and institutions working in the field of heritage conservation

Metodologia para determinação da peroxidase e da polifenol oxidase em plantas.

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Avaliação de genótipos de arroz de sequeiro para tolerância à deficiência hídrica.

O objetivo deste trabalho foi comparar a produtividade de três genótipos de arroz de sequeiro, submetidos a três condições de deficiência hídrica: 30 %, 50 % e 70 % do fornecimento de água dado ao tratamento controle (tratamento sem restrição de água)

Experimental tests for seismic assessment and strengthening of adobe structures

Adobe structures present very appealing characteristics regarding a more sustainable practice with the preservation of our natural resources. However, when subjected to cyclic horizontal actions, such as earthquakes, they can present a deficient behaviour. With the purpose of evaluating the seismic vulnerability of adobe structures, a series of tests were conducted on a full-scale adobe wall considering constant dead and live loads combined with cyclic horizontal actions with rising amplitude. A structural strengthening solution was tested on the repaired wall after its assessment test. The adopted repair solution, based on cracks injection, combined with the strengthening solution, proved to be very efficient in improving the performance of the adobe wall. With the study conducted, it was possible to contribute to the characterization of adobe structural walls in terms of deformation capacity and failure modes, establishing the basis for the calibration of numerical models for adobe structures