The main aim of this study was to evaluate the influence of porosity, microstructure, and chemical composition on the wear and compressive strength of dental glass-ionomer or resin composite. Cylindrical samples (6 9 4 mm) were prepared from a nano-hybrid resin composite (Grandio Ò SO/RC, VOCO), a resin-modified glass ionomer (Vitremer TM /VI, 3 M-ESPE) and a conventional glass ionomer (Ionofil Ò Molar/CO, VOCO). Porosity and topography of the materials were evaluated by optical and scanning electron microscopy (SEM). Roughness was evaluated by R a and R t parameters at 0.1 mm/s under cutoff of 0.8 mm. Then, compressive tests were performed at 1 mm/min. Wear tests were carried out at 20 N, 2.5 mm of displacement, at 1 Hz for 90 min in artificial saliva solution. The results were statistically analyzed with a one-way ANOVA and Tukey's test (p \ 0.05). Resin composite revealed a significantly lower porosity (1.21 ± 0.20 %) than glass-ionomer restoratives (5.69-7.54 %) as well as lower values of R a and R t roughness (p \ 0.05). Also, resin composite showed significantly higher values of mechanical strength (334 ± 15.9 MPa) compared to conventional (78.78 ± 13.30 MPa) or modified glass ionomer (169.50 ± 20.98 MPa) (p \ 0.05). For maximal depth of wear, resin composite also showed significantly lower values than glass ionomer (p \ 0.05). Homogeneous wear morphology was noticed by SEM analyses on glass ionomers in opposition to resin composite. Glass ionomers showed a poor mechanical behavior associated to a high porosity and wear rate when compared to resin composite.

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Coastal zones are naturally dynamic and mobile systems exposed to natural factors (river flows, waves and storms) as well as human interventions that continuously reshape their morphology. Erosion phenomena related to extreme weather events and sediment scarcity are common, threatening buildings and infrastructures, as well as beaches, ecosystems and valuable wetland; conditions that pose challenges to coastal security and defence. Regular monitoring of coastal areas, assessment of their morphodynamics and identification of the processes influencing sediment transport are thus increasingly important for a better understanding of changes and evolutionary trends in coastal systems. This demands a multidisciplinary approach involving researchers with expertise in coastal processes and state-of-the-art observation technologies. In this paper state-of-the-art surveying methods for an efficient quantification of changes in coastal environments are described and evaluated, and two NW-Portuguese case studies are presented. Survey methods included: topographic surveys based on terrestrial videogrammetric mobile mapping and aerial photogrammetry; sub-tidal bathymetry with sonar imagery using an Autonomous Surface Vehicle (ASV); as well as field observations, with sediment sampling and beach characterisation. In the first case study, erosion/accretion patterns in the Douro estuary sand spit were analysed, considering its breakwater, river flow, wave and wind effects. Prior to the construction of a detached breakwater, the spit's morphodynamics was related to extreme river flow events, wave and wind conditions; afterwards the spit stabilized its shape and increased its area and volume. In the second case study the coast of Vila Nova de Gaia was broadly analysed, including the shoreface, foreshore and dunes, the characterization of major features and a short-period analysis of installed dynamics. Results obtained from field data, topographical surveys and numerical wave models were combined for an erosion risk assessment, using a methodology specifically developed for the study area. Both monitoring programs achieved their proposed objectives and provided valuable information to the local authorities, as gathered and processed information constitutes a valuable database for coastal planning and for ICZM purposes. They demonstrate the potential of several approaches, supported by advanced technologies, for the study of complex coastal morphodynamic processes.

Paper Number 120 Full paper on enclosed CD-ROMThe behaviour of steelwork connections has long been recognised as complex. A database of test results for connection behaviour constitutes an essential step towards the development of design methodologies, allowing more researchers to investigate in this field without the financial burden of carrying out experimental work, avoiding being misled by incomplete or incorrect data, and opening the way to design assisted by testing.A database of experimental results for steel and steel-concrete composite connections is presented which encompasses graphical treatment of data, numerical manipulation and statistical treatment of groups of results, allowing easy comparison of connection behaviour. Simplified constitutive models for the hysteretic behaviour of connections are presented and included in the database for comparison and calibration with experimental results.The database SERIWWW was developed according to the following specifications: