Photochromism of the complex between 40-(2-hydroxyethoxy)-7-hydroxyflavylium and b-cyclodextrin, studied by 1H NMR, UVeVis, continuous irradiation and circular dichroism

1st International Caparica Conference on Chromogenic and Emissive Materials

Development of the composition of oak wood during seasoning and its impact on wine

Mestrado Vinifera Euromaster - Instituto Superior de Agronomia - UL

An overview of the submerged sea caves of Sagres (South of Portugal-Algarve)

The submerged sea caves of Sagres are located within the “Parque Natural do Sudoeste Alentejano e Costa Vicentina (PNSACV)” Marine Protected Area (MPA). This MPA integrates the national network of protected areas, addressed by the National Institute for Nature Conservation and Forest (ICNF) and was declared Site of Community Importance (SCI) under the Habitats Directive. Under the Annex I from the Habitat Directive these habitat caves are included in “8330 Submerged or partially submerged sea caves”. This conservation status should provide sufficient concern to have detailed information on biodiversity. However, among marine researcher, little is still known about these submerged sea caves and tunnels habitats. The only well-known study dealing with the Sagres sea caves was conducted in the late 80s and was only published in 2001. For effective management of such specific habitats a clear understanding of their localization and extension, the assessment of the biological communities, its conservation importance, its monitoring options and their sensitivity to natural change and human disturbance need to be a relatively clear. This report, produced under the MeshAtlantic Project, provides an overview of the available published and unpublished information relevant for the conservation management of the subtidal caves of Sagres. It mainly aims to be a base contribution for future studies.

Influence of the metal precursor on the catalytic behavior of Pt/Ceria catalysts in the preferential oxidation of CO in the presence of H2 (PROX)

The effect of the metal precursor (presence or absence of chlorine) on the preferential oxidation of CO in the presence of H2 over Pt/CeO2 catalysts has been studied. The catalysts are prepared using (Pt(NH3)4)(NO3)2 and H2PtCl6, as precursors, in order to ascertain the effect of the chlorine species on the chemical properties of the support and on the catalytic behavior of these systems in the PROX reaction. The results show that chloride species exert an important effect on the redox properties of the oxide support due to surface chlorination. Consequently, the chlorinated catalyst exhibits a poorer catalytic activity at low temperatures compared with the chlorine-free catalyst, and this is accompanied by a higher selectivity to CO2 even at high reaction temperatures. It is proposed that the CO oxidation mechanism follows different pathways on each catalyst.

Effect of Urucu oil (Brazilian Amazon) on the biomass of the aquatic macrophyte Eichhornia crassipes (Mart.) Solms (Pontederiaceae)

Os rios e lagos de várzea da província petrolífera de Urucu, na Amazônia Central, são amplamente colonizados por macrófitas aquáticas, que podem ser afetadas por acidentes durante a exploração e o transporte de petróleo. Entre as macrófitas, a espécie flutuante Eichhornia crassipes (aguapé) ocorre abundantemente na região; OBJETIVO: O objetivo desse estudo foi verificar o efeito de diferentes dosagens do petróleo de Urucu (0; 0,5; 1,5 e 3,0 L.m-2) na biomassa viva e morta de E. crassipes e em algumas características físicas e químicas da água; MÉTODOS: O experimento teve oitenta e quatro dias de duração. A cada sete dias foi determinada a biomassa (viva e morta) de E. crassipes e os valores de temperatura, pH, condutividade elétrica e oxigênio dissolvido da água; RESULTADOS: A dosagem de 0,5 L.m-2 foi suficiente para causar mortalidade parcial (48%) em E. crassipes após trinta e cinco dias de exposição ao petróleo. A dosagem de 3,0 L.m-2 causou mortalidade total (100%) em E. crassipes em oitenta e quatro dias de exposição. A decomposição do petróleo e da biomassa morta de E. crassipes provocam a redução do oxigênio dissolvido e do pH, e aumento da condutividade elétrica e de fósforo total na água; CONCLUSÕES: Nós concluímos que um derramamento de petróleo pode provocar mortalidade total em uma população de uma espécie de macrófita, mas não em uma outra. Isto pode alterar a diversidade de espécies de macrófitas na região impactada. No caso de Eichhornia crassipes e Pistia stratiotes, um derramamento de petróleo de Urucu pode favorecer E. crassipes, a espécie menos sensível ao petróleo.

'Laser chemistry' synthesis, physicochemical properties, and chemical processing of nanostructured carbon foams

Laser ablation of selected coordination complexes can lead to the production of metal-carbon hybrid materials, whose composition and structure can be tailored by suitably choosing the chemical composition of the irradiated targets. This 'laser chemistry' approach, initially applied by our group to the synthesis of P-containing nanostructured carbon foams (NCFs) from triphenylphosphine-based Au and Cu compounds, is broadened in this study to the production of other metal-NCFs and P-free NCFs. Thus, our results show that P-free coordination compounds and commercial organic precursors can act as efficient carbon source for the growth of NCFs. Physicochemical characterization reveals that NCFs are low-density mesoporous materials with relatively low specific surface areas and thermally stable in air up to around 600°C. Moreover, NCFs disperse well in a variety of solvents and can be successfully chemically processed to enable their handling and provide NCF-containing biocomposite fibers by a wet-chemical spinning process. These promising results may open new and interesting avenues toward the use of NCFs for technological applications.

Combined atom probe tomography and density functional theory investigation of the Al off-stoichiometry of κ-carbides in an austenitic Fe-Mn-Al-C low density steel

We report on the investigation of the off-stoichiometry and site-occupancy of κ-carbide precipitates within an austenitic (γ), Fe-29.8Mn-7.7Al-1.3C (wt.%) alloy using a combination of atom probe tomography and density functional theory. The chemical composition of the κ-carbides as measured by atom probe tomography indicates depletion of both interstitial C and substitutional Al, in comparison to the ideal stoichiometric L′12 bulk perovskite. In this work we demonstrate that both these effects are coupled. The off-stoichiometric concentration of Al can, to a certain extent, be explained by strain caused by the κ/γ mismatch, which facilitates occupation of Al sites in κ-carbide by Mn atoms (MnγAl anti-site defects). The large anti-site concentrations observed by our experiments, however, can only be stabilized if there are C vacancies in the vicinity of the anti-site.

More favorable combination of circumstances could hardly have been desired : a bottom to top examination of the Pittsburgh and Boston Mining Company's Cliff Mine

The Cliff Mine, an archaeological site situated on the Keweenaw Peninsula of Michigan, is the location of the first successful attempt to mine native copper in North America. Under the management of the Pittsburgh & Boston Mining Company from 1845-1879, two-third of the Cliff’s mineral output was in the form of mass copper, some pieces of which weighed over 5 tons when removed from the ground. The unique nature of mass copper and the Cliff Mine’s handling of it make it one of the best examples of early mining processes in the Keweenaw District. Mass copper only constituted 2% of the entire product of the Lake Superior copper districts, and the story of early mining on the Peninsula is generally overshadowed by later, longer running mines such as the Calumet & Helca and Quincy Mining Companies. Operating into the mid-twentieth century, the size and duration of these later mines would come to define the region, though they would not have been possible without the Cliff’s early success. Research on the Cliff Mine has previously focused on social and popular history, neglecting the structural remains. However, these remains are physical clues to the technical processes that defined early mining on the Keweenaw. Through archaeological investigations, these processes and their associated networks were documented as part of the 2010 Michigan Technological Archaeology Field School’s curriculum. The project will create a visual representation of these processes utilizing Geographic Information Systems software. This map will be a useful aid in future research, community engagement and possible future interpretive planning.

Study of the Electrochemical, Physical and Morphological Characteristics of Anode Catalysts for Perfluorosulfonic Acid (PFSA) Membrane Water Electrolysers

A number of supported and un-supported Oxygen Evolution Reaction (OER) iridium based electrocatalysts for Polymer Electrolyte Membrane Water Electrolysis (PEMWE) were synthesized using a polyol method. The electrocatalysts and the supports were characterized using a wide range of physical and electrochemical characterization methods. The effect of morphological characteristics of the OER electrocatalyst and the support on the OER activity was studied. The results of this thesis contribute to the existing research to reduce the cost of PEMWE by enhancing the utilization of precious metal for OER electrocatalysis. Iridium electrocatalysts supported on antimony tin oxide (Ir/ATO) were synthesized using the polyol method with two different heating techniques: conventional and microwave-irradiation. It was shown that the physical morphology and electrochemical properties of Ir/ATO synthesized with the two heating methods were comparable. However, the microwave irradiation method was extremely faster than the conventional heating method. Additionally, the effect of heat treatment (calcination temperature) on the morphology and OER activity of Ir/ATO synthesized electrocatalyst with the conventional polyol method. It was found that the iridium electrocatalyst synthesized with the polyol method, consisted of 1-5 nm particles, possessed an amorphous structure, and contained iridium with an average oxidation state of less than +4. Calcining the catalyst at temperatures more than 400 ºC and less than 700ºC: 1) increased the size of the iridium particles to 30 nm, 2) changed the structure of iridium particles from amorphous to crystalline, 3) increased the iridium oxidation state to +4 (IrO2), 4) reduced the electrochemically active surface area by approximately 50%, and 5) reduced the OER activity by approximately 25%; however, it had no significant effect on the physical and chemical morphology of the ATO support. Moreover, potential support metal carbides and oxides including: Tantalum Carbide (TaC), Niobium Oxide (Nb2O5), Niobium Carbide (NbC), Titanium Carbide (TiC), Tungsten Carbide (WC) and Antimony-doped Tin Oxide (ATO, Sb2O5-SnO2), were characterized, and used as support for the iridium OER electrocatalysts. TaC was found to be a promising support, and increasing its surface area by 4% improved the OER performance of the final supported catalyst by approximately 50%.

Population structure of the black seabream Spondyliosoma cantharus along the south-west Portuguese coast inferred from otolith chemistry

The chemistry of black seabream Spondyliosoma cantharus otoliths from three main fishery grounds (Olhao, Sagres and Sesimbra) located along c. 400 km of the Portuguese south and west coasts was examined. Element:Ca ratios were determined in whole otoliths and otolith cores of young adult specimens of 23 years of age. Using the data from whole otoliths, it was possible to discriminate among S. cantharus from the three fishing grounds with an average accuracy of 91%. Differences among fishing grounds were significant for all element:Ca ratios, and otoliths from Sagres had significantly higher levels of all ratios compared to the other fishing grounds. In contrast, the chemical composition of the otolith core, representative of the larval stage, showed limited variation among the fishing grounds, with an average discrimination accuracy of only 44%, although the Mg:Ca ratio of the otolith cores was also significantly higher for the Sagres samples. The data suggest that larval stages experienced a homogenous environment consistent with an offshore oceanic spawning. Juveniles appeared to display local residency on the inshore fishing grounds, areas probably characterized by greater environmental heterogeneity. Spondyliosoma cantharus population structure is consistent with distinct local population units that share a spawning ground providing recruits to different coastal fishery areas.

Catches of the sport fishing competitions along the Algarve coast (Portugal): species, sizes, catch rates, and trends

Background. Stocks of many marine fishes are in decline and a number of studies suggest that for some species the impact of recreational angling may be important. To date, only recreational (leisure) fishing surveys have been conducted in Portugal, with no studies on beach angling competitions, dynamically increasing in number over the past 10 to 20 years. In view of the above, we decided to evaluate the impact of such events on the Algarve coast (southern Portugal) in terms of the abundance, diversity, and respective weight of fish species caught and outline some conservation measures and recommendations for the management of the targeted species. Materials and methods. Participants of 22 angling competitions taking place between February and June 2007 were surveyed. In each competition a random sample of anglers was interviewed, and the specimens caught by each participant were identified, weighed, and measured. Results. Thirteen taxa belonging to eight families were identified, and the most common were: garfish, Belone belone (Linnaeus, 1761); mullets, Mugilidae (not identified); and mackerels, Scomber spp. A total of 563 specimens were sampled, totalling 75.4 kg of weight, with the average catch per angler weighing 0.5 +/- 0.05 SE (n = 153) kg. Differences were also observed between the length at first maturity (L(50)) of the specimens caught and their respective Minimum Landing Size (MLS) and Allowed Minimum Size (AMS), most particularly in the case of the European seabass, Dicentrarchus labrax (L.), with almost all individuals caught measuring below the species-specific L50. Analysis of time series of competition results (1996-2009) showed no evidence of a decrease in catches or in mean weight. Conclusion. Based on the results we propose that the AMS for beach angling competitions should be increased to the MLS in order to prevent the capture of juvenile fishes, especially the sea bass. Future studies should address the size selectivity of the hooks used in beach competitions, with a view to the implementation of a minimum hook size for competitions.

Biotic and abiotic parameters that distinguish types of temporary ponds in a Portuguese Mediterranean ecosystem

Temporary ponds are seasonal wetland habitats subjected to extreme and unstable ecological conditions. Some are classified as priority habitats for conservation by the European Union Habitats Directive. Our study area was the coastal plain of southwest Portugal, which spans across 100km north to south and hosts a large number of temporary ponds as a consequence of climatic and edaphic characteristics. Field sampling of floristic and edaphic data was carried out in 24 temporary ponds every spring between 2005 and 2008. We recorded a total of 174 plant species identified within visually homogeneous plots. We included the data in a geographic information system and classified ponds according to their floristic composition, using a biotic regionalization analysis based on species presence/absence, which is a practical and unambiguous criterion. We found three significantly different groups of ponds which corresponded to an eco-physiognomic pond typology: Mediterranean temporary ponds, marshlands, and disturbed ponds. For the first two pond types we defined characteristic or indicator plant species. We searched also for relationships between pond type and a series of large-scale climatic, geographic, and geological variables, as well as local-scale physical and chemical properties of the soil. Pond type was distinguished by a complex combination of some of these variables, including environmental energy, soil texture, nitrogen content of the soil and pH. A practical way of discriminating between different

Living on the intertidal/subtidal edge: ecology of the stalked barnacle Pollicipes Pollicipes and of the sea urchin Paracentrotus lividus

This thesis contributes to the knowledge of temperate rocky shore ecology, with direct implications in the management and conservation of two important local marine resources that inhabit the very edge of subtidal and intertidal habitats on wave-swept rocky shores: the sessile filter feeding stalked barnacle Pollicipes pollicipes and the mobile keystone herbivore sea urchin Paracentrotus lividus. Research was conducted along gradients of wave exposure on rocky shores of Southern Europe. The abundance of P. lividus was four times higher in SW Portugal than in NW Italy. Most of the variation in urchin abundance occurred at small spatial scales, probably shaped by habitat complexity. In SW Portugal, sea urchin attachment forces while in burrows were measured and related to burrow shape, urchin size and habitat. Burrowing behaviour enhances sea urchin attachment force and might be an adaptive response to hydrodynamic stress. Abundance of P. pollicipes in SW Portugal is highly and positively related to wave exposure at local and regional scales. Predation and recruitment processes seem to be important drivers of these abundance patterns. A distribution model of P. pollicipes abundance in relation to wave exposure was developed for the SW coast of Portugal and might be used for improvement of its management and conservation. Growth of P. pollicipes was studied by applying a novel method using fluorescent calcein for marking and to estimate growth. Growth rate decreased with barnacle size and was highly variable amongst individuals, particularly in smaller barnacles. No effect of shore level on barnacle growth was detected. An assessment of the state of the fishery, conservation and management of the stalked barnacle in different regions of continental Portugal was made, highlighting an overall negative tendency of this state and recommending a change into a co-management system; Resumo: Viver no limite intertidal / subtidal: ecologia do percebe Pollicipes pollicipes e do ouriço-do-mar Paracentrotus lividus Esta tese contribui para o conhecimento da ecologia do litoral rochoso e tem implicações diretas na gestão e conservação de dois recursos marinhos locais que habitam o interface subtidal/intertidal de costas rochosas sujeitas a agitação marinha: o percebe Pollicipes pollicipes, animal séssil e filtrador e o ouriço-do-mar Paracentrotus lividus, animal móvel e herbívoro. Foram realizados vários estudos ao longo de gradientes de hidrodinamismo em costas rochosas do sul da Europa. A abundância de P. lividus foi quatro vezes superior no sudoeste de Portugal relativamente ao noroeste de Itália. Grande parte da variação na abundância de P. lividus ocorreu a pequenas escalas espaciais, provavelmente influenciada pela complexidade do habitat. A força com que o ouriço-do-mar se fixa ao substrato foi medida no terreno no sudoeste de Portugal, tendo esta sido relacionada com a forma da depressão que ocupa, o tamanho individual e o habitat. O comportamento escavador desta espécie aumenta a sua força de fixação ao substrato e poderá ser uma resposta adaptativa ao hidrodinamismo.. A abundância de P. pollicipes na costa sudoeste de Portugal, a diferentes escalas espaciais, está relacionada de forma positiva com a agitação marinha, e é influenciada pela predação e pelo recrutamento desta espécie. Foi desenvolvido um modelo de distribuição e abundância de P. pollicipes para esta costa baseado na relação com a agitação marinha, cujos resultados podem ser usados para melhorar a gestão e conservação deste recurso. Um novo método com recurso a calceina fluorescente foi desenvolvido para marcar percebes e estudar o seu crescimento. A taxa de crescimento diminuiu com o tamanho do animal, sendo altamente variável entre indivíduos, sobretudos nos de menores dimensões. O estado da apanha, conservação e gestão do percebe em diferentes regiões de Portugal Continental apresentou uma tendência global negativa, e recomenda-se uma alteração para um sistema de cogestão deste recurso.

Enzymatic activity on sediments and nematode assemblage responses during seagrass beds habitat recovery following the disturbance of the traditional digging activity of bivalves harvesting.

Sediment digging is an anthropogenic activity connected to the exploitation of living resources in estuarine and marine environments. The knowledge on the functional responses of the benthic assemblages to the physical disturbance is an important baseline to understand the ecological processes of the habitat recovery and restoration and to develop tools for the management of the harvesting activities. To investigate the effects of the digging activity of the bivalves on Zostera noltii seagrass beds a manipulative field experiment was conducted that included the enzymatic activity of sediments and the associated nematode assemblages. Four plots (two undisturbed serving as control and two dug to collect bivalves - treatment) with 18 subplots were randomly located at seagrass beds in the Mira estuary at the SW coast of Portugal. Samples were randomly and unrepeatably collected from three subplots of each plot in five different occasions, before sediment digging (T0) up to six months after disturbance (T5). Microbial activity in sediments was assess by determining the extracelular enzymatic activity of six hydrolytic enzymes (sulfatase, phosphatase, b -N-acetilglucosaminidase, b-glucosidase, urease, protease) and two oxidoreductases (phenol oxidase and peroxidase). The microbial community status was also assessed through the measurement of dehydrogenase, which reflects microbial respiration. The nematode assemblages composition, biodiversity and trophic composition at different sampling occasions were also analyzed. The fluorometric and biochemical parameters analysed of the Z. noltii plants during the experimental period showed a recovery of the seagrass beds, and it was detected an increase of the enzymatic activity of the sediments after disturbance. The nematodes assemblages were similar in all sampling occasions. The seagrass beds and the nematodes assemblages associated showed a high resilience to the stress caused by the traditional bivalves digging activity. The obtained results allow the development of a management programme for the commercial fishing activity to maintain the good environmental status and minimized the secondary environmental effects on marine and estuarine habitats through the establishment of a baseline for the regulation of the harvesting frequency.

Caracterização química de um solo contaminado por resíduos sólidos urbanos na estrada Arroio Pavuna em Jacarepaguá no município Rio de Janeiro

Neste trabalho, escolheu-se a estrada canal Arroio Pavuna, em Jacarepaguá, para avaliar quimicamente a qualidade do solo que recebe diariamente resíduos sólidos urbanos. A região deste estudo é também conhecida como estrada do Urubu, sendo este animal um dos principais vetores presente no local. Para uma caracterização química, foram determinados pH, carbono orgânico, matéria orgânica, concentrações dos metais alumínio, cádmio, chumbo, cobre, cromo, ferro, níquel e zinco, utilizando a técnica de Absorção Atômica por Chama, além da identificação dos principais compostos orgânicos através da técnica de Cromatografia Gasosa acoplada a Espectrometria de Massas. Também foi realizado o teste de comportamento com oligoquetas da espécie Eisenia andrei para avaliar a função de habitat do solo analisado. Os resultados obtidos apontaram que a região apresenta um solo ácido na faixa de 5,51 a 6,70, bem como as concentrações de Cobre, Cromo, Níquel e Zinco acima dos valores orientadores de referência de qualidade dos solos, um teor médio de matéria orgânica na faixa de 21,71 g.kg-1 a 29,73 g.kg-1, além de presença de compostos orgânicos com estruturas muito complexas. O solo apresentou função de habitat limitada. E como sugestão para a remediação deste solo, a fitorremediação apresenta bons rendimentos na literatura para remoção parcial ou total desses metais