The experimental results obtained in a wide range of temperatures, for polyethylene terephthalate, demonstrate that the apparent activation energy changes when the charging (polarization) time or the isothermal discharging time, prior to the final thermally stimulated discharge current measurement, are used as variable parameters. Consequently, the charging and/or discharging time can be used as a variable parameter to investigate the landscape of the apparent thermal activation energies. A continuous distribution of the traps in the range from 0.4 to 3 eV was observed. The experimental results demonstrate that there is a range of experimental conditions for which the thermal activation energy is independent of the experimental parameter values. This is the activation energy value which should be used to characterize a certain mechanism.

The experimental results obtained in a wide range of temperatures, for polyethylene terephthalate, demonstrate that the apparent activation energy changes when the charging (polarization) time or the isothermal discharging time, prior to the final thermally stimulated discharge current measurement, are used as variable parameters. Consequently, the charging and/or discharging time can be used as a variable parameter to investigate the landscape of the apparent thermal activation energies. A continuous distribution of the traps in the range from 0.4 to 3 eV was observed. The experimental results demonstrate that there is a range of experimental conditions for which the thermal activation energy is independent of the experimental parameter values. This is the activation energy value which should be used to characterize a certain mechanism.

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A new silylated $\alpha$-diimine ligand, bis[N,N′-(4-tert-butyl- diphenylsilyl-2,6-diisopropylphenyl)imino]acenaphthene 3, and its corresponding Ni(II) complex, {\{}bis[N,N′-(4-tert-butyl-diphenylsilyl-2,6- diisopropylphenyl)imino]acenaphthene{\}}dibromonickel 4, have been synthesized and characterized. The crystal structures of 3 and 4 were determined by X-ray crystallography. In the solid state, complex 4 is a dimer with two bridging Br ligands linking the two nickel centers, which have square pyramidal geometries. Complex 4, activated either by diethylaluminum chloride (DEAC) or methylaluminoxane (MAO) produces very active catalyst systems for the polymerization of ethylene and moderately active for the polymerization of propylene. The activity values are in the order of magnitude of 107 g PE (mol Ni [E] h)-1 for the polymerization of ethylene and of 105 g PP (mol Ni [P] h)-1 for the polymerization of propylene. NMR analysis shows that branched polyethylenes (PE) are obtained at room or higher temperatures and almost linear PE is obtained at 0°C with 4/DEAC. © 2004 Elsevier B.V. All rights reserved.

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An orange-coloured protein (ORP) isolated from Desulfovibrio gigas, a sulphate reducer, has been previously shown by extended X-ray absorption fine structure (EXAFS) to contain a novel mixed-metal sulphide cluster of the type {[}S2MoS2CuS2MoS2] {[}J. Am. Chem. Soc. 122 (2000) 8321]. We report here the purification and the biochemical/spectroscopic characterisation of this novel protein. ORP is a soluble monomeric protein (11.8 kDa). The cluster is non-covalently bound to the polypeptide chain. The presence of a MoS42- moiety in the structure of the cofactor contributes with a quite characteristic UV-Vis spectra, exhibiting an orange colour, with intense absorption peaks at 480 and 338 nm. Pure ORP reveals an Abs(480)/Abs(338) ratio of 0.535. The gene sequence coding for ORP as well as the amino acid sequence was determined. The putative biological function of ORP is discussed. (C) 2003 Elsevier Inc. All rights reserved.

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The present work reports results obtained from a series of preliminary experiments
aiming at complementing the current knowledge about the wear behaviour of centrifugally-cast
FGM Al/SiCp composites, through concurrent corrosion processes. Precursor MMC’s were
prepared by rheocasting, using 118.8 μm SiC particles and an Al-10Si–2.2 Mg alloy. Those MMC’s
were then molten and centrifugally cast in order to produce cylindrical FGMMC’s. Discs machined
from the top surface of each sample were tested against nodular cast iron pins, using an inverted
configuration pin-on-disc tribometer. Sliding tests took place at room temperature, over a 50000 m
sliding distance, with a sliding speed of 0.3 m s-1, under a 5 N normal load; both dry-sliding and
water-lubricated tests were performed. In order to elucidate the mechanisms involved, the wear
coefficients were calculated for each condition, and the samples were subjected to morphological
characterization via SEM/EDS. Concurrently, in the case of the water-lubrication tests, the
corrosion potential of the tribological pair was monitored. The results obtained show an increase in
material loss for the water-lubricated cases, although variations are registered depending on
reinforcing particle volume fraction. At the same time, the open circuit potential response of the
tribological pair may be correlated with the events of formation/destruction of the tribolayers.

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The main aim of the Valomat project was the development of new materials for quarry back-filling and underground constructions, based on the reuse of bottom ashes from MSWI. Bottom ashes were collected in six incineration plants of Europe. Some of them were selected for the development of new materials.
One task of this project comprised the study of the long-term behavior of new materials, under simulated conditions of environmental exposure. Three different scenarios were studied. For each scenario, a pilot plant was constructed and the new materials were studied under laboratory conditions or natural weather. The long-term behavior of these materials was assessed through the characterization of chemical and ecotoxicological properties of the leachates.
The chemical contamination and the ecotoxicological levels of the leachates were relatively low, although different levels had been determined for the three different scenarios. The immersion in dechlorinated tap water (scenario S1) had shown the highest emission levels of chlorides, sulphates, DOC, and Al, especially for the materials B2/1 and B2/2. The lowest ecotoxicological and chemical levels were determined in the scenario in which the materials were buried in a sieved soil.

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In the last decade a considerable amount of research work has focused on distributed debugging, one of the crucial fields in the parallel software development cycle. The productivity of the software development process strongly depends on the adequate definition of what debugging tools should be provided, and what debugging methodologies and functionalities should these tools support. The work described in this dissertation was initiated in 1995, in the context of two research projects, the SEPP (Software Engineering for Parallel Processing) and HPCTI (High-Performance Computing Tools for Industry), both sponsored by the European Union in the Copernicus program, which aimed at the design and implementation of an integrated parallel software development environment. In the context of these projects, two independent toolsets have been developed, the GRADE and EDPEPPS parallel software development environments. Our contribution to these projects was in the debugging support. We have designed a debugging engine and developed a prototype, which was integrated the both toolsets (it was the only tool developed in the context of the SEPP and HPCTI projects which achieved such a result). Even after the closing of those research projects, further research work on distributed debugger has been carried on, which conducted to the re-design and re-implementation of the debugging engine. This dissertation describes the debugging engine according to its most up-to-date design and implementation stages. It also reposts some of the experimental work made with both the initial and the current implementations, and how it contributed to validate the design and implementations of the debugging engine.

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The Water Company of the North Alentejo (Águas do Norte Alentejano) (Portugal) has decided to implement a treatment plant to treat an urban wastewater with a significant influence of tannery effluents. The design of the wastewater treatment plant was attributed to a consortium coordinated by Sisaqua Company. Since the levels of the biodegradability and toxicity of the wastewater to be treated were unknown, Sisaqua Company asked the New University of Lisboa to develop and execute a monitoring plan to define the chemical composition and the levels of the biodegradability and toxicity of the wastewater.
A composite sampling procedure of the wastewater was performed during a daily working cycle of the tanneries. The composite sample was characterized for 19 chemical parameters. Five of these parameters were total Cr, Cr (VI), Zn, Cu and Al, which were determined in the dissolved and suspended fractions. The composite sample was also submitted to a biological test to assess its biodegradability degree. This assay was performed according to the methodology indicated in the test 301E of OECD [1], taking into account the amendment of 1992. A respirometric assay was carried out, to assess the toxic effect of the composite sample on the biological populations involved in the biological stabilization of organic compounds. This assay followed the “Sapromat” methodology developed by Brabander and Vandeputte [2]. Finally, the composite sample was submitted to a coagulation-flocculation process according to the methodologies proposed by Eckenfelder [3, 4] and Pereira [5]. The supernatants were characterized for the same chemical and biological parameters as it was described for the composite sample.
It was possible to conclude that the high levels of Cr present in the composite wastewater were mainly in the trivalent oxidation state. Since this oxidation state is less toxic for biological populations than the Cr (VI) and this metal was mainly in the suspended fraction, it was possible to obtain a biodegradability of the organic compounds quite similar to those observed for domestic wastewaters. The toxicity determined by the “Sapromat” method was slightly higher than those determined for domestic wastewaters. Nevertheless, this toxicity did not affect significantly the wastewater biodegradability. The Cr (III) was easily removed by a chemical coagulation-flocculation process.

An orange-coloured protein (ORP) isolated from Desulfovibrio gigas, a sulphate reducer, has been previously shown by extended X-ray absorption fine structure (EXAFS) to contain a novel mixed-metal sulphide cluster of the type [S2MoS2CuS2MoS2] [J. Am. Chem. Soc. 122 (2000) 8321]. We report here the purification and the biochemical/spectroscopic characterisation of this novel protein. ORP is a soluble monomeric protein (11.8 kDa). The cluster is non-covalently bound to the polypeptide chain. The presence of a MoS42- moiety in the structure of the cofactor contributes with a quite characteristic UV-Vis spectra, exhibiting an orange colour, with intense absorption peaks at 480 and 338 nm. Pure ORP reveals an Abs(480)/Abs(338) ratio of 0.535. The gene sequence coding for ORP as well as the amino acid sequence was determined. The putative biological function of ORP is discussed. (C) 2003 Elsevier Inc. All rights reserved.