Valorização do sistema construtivo do património edificado

Este trabalho analisa a valorização e salvaguarda do sistema construtivo das edificações de arquitetura civil do século XIX, frente às intervenções a que são submetidas, diante da necessidade de adaptação a usos e funções da vida contemporânea. Tem como estudo de caso o centro histórico de São Luís do Maranhão. Para sua elaboração, foram desenvolvidas as seguintes etapas: fundamentação teórica e conceitual do tema; análise dos aspectos da organização físico-espacial da arquitetura produzida no século XIX; leitura, análise e interpretação da constituição tipológica e estado de conservação do acervo arquitetônico do centro histórico de São Luís e verificação das intervenções referentes à conservação da integridade do sistema construtivo. Além da pesquisa, o trabalho apresenta algumas recomendações sobre a conservação da autenticidade do sistema construtivo das edificações patrimoniais, como forma de contribuição para orientar futuras intervenções de reabilitação.

Processo criativo |ENTRE| convite à produção

O presente trabalho propõe-se como exploração de um artista-pesquisador que procura compreender o próprio trabalho aquando da sua produção. O trabalho é composto pela procura e influências ocorridos aquando de uma exploração própria do artista-pesquisador, que procura territorializar e compreender o seu trabalho em desenvolvimento. O objeto em produção é uma curta-metragem em cinema de animação de autor, alvo de diversas interferências e condicionantes. A procura de uma reflexão na produção própria contribui para o conhecimento em investigação próprio dos artistas visuais.

Microbe-mediated recovery of salt marshes contaminated with oil hydrocarbons

Salt marshes are highly productive intertidal habitats that serve as nursery grounds for many commercially and economically important species. Because of their location and physical and biological characteristics, salt marshes are considered to be particularly vulnerable to anthropogenic inputs of oil hydrocarbons. Sediment contamination with oil is especially dangerous for salt marsh vegetation, since low molecular weight aromatic hydrocarbons can affect plants at all stages of development. However, the use of vegetation for bioremediation (phytoremediation), by removal or sequestration of contaminants, has been intensively studied. Phytoremediation is an efficient, inexpensive and environmental friendly approach for the removal of aromatic hydrocarbons, through direct incorporation by the plant and by the intervention of degrading microbial populations in the rhizosphere (microbe-assisted phytoremediation). Rhizosphere microbial communities are enriched in important catabolic genotypes for degradation of oil hydrocarbons (OH) which may have a potential for detoxification of the sediment surrounding the roots. In addition, since rhizosphere bacterial populations may also internalize into plant tissues (endophytes), rhizocompetent AH degrading populations may be important for in planta AH degradation and detoxification. The present study involved field work and microcosms experiments aiming the characterization of relevant plant-microbe interactions in oilimpacted salt marshes and the understanding of the effect of rhizosphere and endosphere bacteria in the role of salt marsh plants as potential phytoremediation agents. In the field approach, molecular tools were used to assess how plant species- and OH pollution affect sediment bacterial composition [bulk sediment and sediment surrounding the roots (rhizosphere) of Halimione portulacoides and Sarcocornia perennis subsp. perennis] in a temperate estuary (Ria de Aveiro, Portugal) chronically exposed to OH pollution. In addition, the 16S rRNA gene sequences retrieved in this study were used to generate in silico metagenomes and to evaluate the distribution of potential bacterial traits in different microhabitats. Moreover, a combination of culture-dependent and -independent approaches was used to investigate the effect of oil hydrocarbons contamination on the structure and function of endophytic bacterial communities of salt marsh plants.Root systems of H. portulacoides and S. perennis subsp. perennis appear to be able to exert a strong influence on bacterial composition and in silico metagenome analysis showed enrichment of genes involved in the process of polycyclic aromatic hydrocarbon (PAH) degradation in the rhizosphere of halophyte plants. The culturable fraction of endophytic degraders was essentially closely related to known OH-degrading Pseudomonas species and endophytic communities revealed sitespecific effects related to the level of OH contamination in the sediment. In order to determine the effects of oil contamination on plant condition and on the responses in terms of structure and function of the bacterial community associated with plant roots (rhizosphere, endosphere), a microcosms approach was set up. The salt marsh plant Halimione portulacoides was inoculated with a previous isolated Pseudomonas sp. endophytic degrader and the 2-methylnaphthalene was used as model PAH contaminant. The results showed that H. portulacoides health and growth were not affected by the contamination with the tested concentration. Moreover, the decrease of 2-methylnaphthalene at the end of experiment, can suggest that H. portulacoides can be considered as a potential plant for future uses in phytoremedition approaches of contaminated salt marsh. The acceleration of hydrocarbon degradation by inoculation of the plants with the hydrocarbon-degrading Pseudomonas sp. could not, however, be demonstrated, although the effects of inoculation on the structure of the endophytic community observed at the end of the experiment indicate that the strain may be an efficient colonizer of H. portulacoides roots. The results obtained in this work suggest that H. portulacoides tolerates moderate concentrations of 2-methylnaphthalene and can be regarded as a promising agent for phytoremedition approaches in salt marshes contaminated with oil hydrocarbons. Plant/microbe interactions may have an important role in the degradation process, as plants support a diverse endophytic bacterial community, enriched in genetic factors (genes and plasmids) for hydrocarbon degradation.

Monitoring and all-optical signal processing techniques for transparent networks

Optical networks are under constant evolution. The growing demand for dynamism require devices that can accommodate different types of traffic. Thus the study of transparent optical networks arises. This approach makes optical networks more "elegant" , due to a more efficient use of network resources. In this thesis, the author proposes devices that intend to form alternative approaches both in the state of art of these same technologies both in the fitting of this technologies in transparent optical networks. Given that full transparency is difficult to achieve with current technology (perhaps with more developed optical computing this is possible), the author proposes techniques with different levels of transparency. On the topic of performance of optical networks, the author proposes two techniques for monitoring chromatic dispersion with different levels of transparency. In Chapter 3 the proposed technique seems to make more sense for long-haul optical transmission links and high transmission rates, not only due to its moderate complexity but also to its potential moderate/high cost. However it is proposed to several modulation formats, particularly those that have a protruding clock component. In Chapter 4 the transparency level was not tested for various modulation formats, however some transparency is achieved by not adding any electrical device after the receiver (other than an analog-digital converter). This allows that this technique can operate at high transmission rates in excess of 100 Gbit / s, if electro-optical asynchronous sampling is used before the optical receiver. Thus a low cost and low bandwidth photo-detector can be used. In chapter 5 is demonstrated a technique for simultaneously monitoring multiple impairments of the optical network by generating novel performance analysis diagrams and by use of artificial neural networks. In chapter 6 the author demonstrates an all-optical technique for controlling the optical state of polarization and an example of how all-optical signal processing can fully cooperate with optical performance monitoring.

Marionetas: das personagens à descoberta do mundo

Com este trabalho desenvolvemos um projeto que permitiu descobrir o mundo e a diversidade das suas culturas e figuras humanas, tendo como mediação a construção de um conjunto de marionetas que caraterizassem figuras representativas de diferentes continentes.

Integer-valued APARCH processes in the analysis of time series of counts

The Asymmetric Power Arch representation for the volatility was introduced by Ding et al.(1993) in order to account for asymmetric responses in the volatility in the analysis of continuous-valued financial time series like, for instance, the log-return series of foreign exchange rates, stock indices or share prices. As reported by Brannas and Quoreshi (2010), asymmetric responses in volatility are also observed in time series of counts such as the number of intra-day transactions in stocks. In this work, an asymmetric power autoregressive conditional Poisson model is introduced for the analysis of time series of counts exhibiting asymmetric overdispersion. Basic probabilistic and statistical properties are summarized and parameter estimation is discussed. A simulation study is presented to illustrate the proposed model. Finally, an empirical application to a set of data concerning the daily number of stock transactions is also presented to attest for its practical applicability in data analysis.

Ecological and biotechnological potential of sponge microbiome

Marine sponges harbor microbial communities of immense ecological and biotechnological importance. Recently, they have been focus of heightened attention due to the wide range of biologically active compounds with potential application, particularly, in chemical, cosmetic and pharmaceutical industries. However, we still lack fundamental knowledge of their microbial ecology and biotechnological potential. The development of high-throughput sequencing technologies has given rise to a new range of tools that can help us explore the biotechnological potential of sponges with incredible detail. Metagenomics, in particular, has the power to revolutionize the production of bioactive compounds produced by unculturable microorganisms. It can offer the identification of biosynthetic genes or gene clusters that can be heterologously expressed on a cultivable and suitable host. This review focus on the exploration of the biotechnological potential of sponge-associated microorganisms, and integration of molecular approaches, whose increasing efficiency can play an essential role on achieving a sustainable source of natural products.

Post-synthetic modification of metal–organic frameworks

Post-synthetic modification (PSM) of metal-organic frameworks encompassing the chemical transformation of the linker present is a promising new route for engineering optical centres and tuning the light emission properties of materials, both in the visible and in the near infrared (NIR) spectral regions. Here, PSM of isoreticular metal-organic framework-3 (IRMOF-3) with ethyl oxalyl monochloride, ethyl acetoacetate, pentane-2,4-dione, 3-(2- hydroxyphenyl)-3-oxopropanal, 2-chloroacetic acid, glyoxylic acid, methyl vinyl ketone and diethyl (ethoxymethylene)malonate followed by chelation of trivalent lanthanide ions afforded intriguing near infrared (Nd3+) and visible (Eu3+, Tb3+) light emitters. IRMOF-3 was used as a case in point due to both its highly porous crystalline structure and the presence of non-coordinating amino groups on the benzenedicarboxylate (bdc) linker amenable to modification. The materials were characterised by elemental analysis, powder X-ray diffraction, optical, scanning and transmission electron microscopy, Fourier transform infrared spectroscopy, and liquid and solid-state nuclear magnetic resonance. The solid-state luminescence properties of Ln-modified-IRMOF-3 were investigated at room temperature. The presence of the bdc aromatic ring, β– diketonate and oxalate enhanced the Ln3+ sensitization via ligand-to-metal energy transfer (anthena effect). As far as photocalysis is concerned, we have synthesized metal−organic frameworks (Cr-MIL-125-AC, Ag-MIL-125-AC) by a green method (solid–vapors reactions). The resulting functionalized materials show a photocatalytic activity for methylene blue degradation up to 6.52 times larger than that of the commercial photocatalyst hombikat UV-100. These findings open the door for further research for improving the photocatalytic performance of metal-organic frameworks.