Char residues produced in the co-pyrolysis of different wastes (plastics, pine biomass and used tyres) were characterized using chemical and toxicity assays. One part of the solid chars was submitted to extraction with dichloromethane (DCM) in order to reduce the toxicity of the char residues by removing organic contaminants. The different volatility fractions present in the extracted char (Char A) and in the raw char (Char B) were determined by progressive weight loss combustion. A selected group of heavy metals (Cd, Pb, Zn, Cu, Hg and As) was determined in both chars.

The chars were subjected to the leaching test ISO/TS 21268 – 2, 2007 and the resulting eluates were further characterized by determining a group of inorganic parameters (pH, conductivity, Cd, Pb, Zn, Cu, Hg and As contents) and the concentrations of several organic contaminants (volatile aromatic hydrocarbons and alkyl phenols). An ecotoxicological characterization was also performed by using the bio-indicator Vibrio fischeri.

The chemical and ecotoxicological results were analyzed according to the Council Decision 2003/33/CE and the criteria on the evaluation methods of waste ecotoxicity (CEMWE).

The results obtained in this work indicated that the extraction with DCM is an effective method for the removal of organic contaminants of high to medium volatility from pyrolysis solid residues, thus decreasing their toxicity potential. Zn can be leached from the chars even after the DCM extraction treatment and can contribute to the ecotoxicity of the eluates obtained from chars.

Both chars (treated and non treated with DCM) were classified as hazardous and ecotoxic wastes.

Spreadsheets are notoriously error-prone. To help avoid the introduction of errors when changing spreadsheets, models that capture the structure and inter-dependencies of spreadsheets at a conceptual level have been proposed. Thus, spreadsheet evolution can be made safe within the confines of a model. As in any other model/instance setting, evolution may not only require changes at the instance level but also at the model level. When model changes are required, the safety of instance evolution can not be guarded by the model alone. Coupled transformation of models and instances are supported by the 2LT platform and have been applied for transformation of algebraic datatypes, XML schemas, and relational database models. We have extended 2LT to spreadsheet evolution. We have designed an appropriate representation of spreadsheet models, including the fundamental notions of formulæ, references, and blocks of cells. For these models and their instances, we have designed coupled transformation rules that cover specific spreadsheet evolution steps, such as extraction of a block of cells into a separate sheet or insertion of columns in all occurrences of a repeated block of cells. Each model-level transformation rule is coupled with instance level migration rules from the source to the target model and vice versa. These coupled rules can be composed to create compound transformations at the model level that induce compound transformations at the instance level. With this approach, spreadsheet evolution can be made safe, even when model changes are involved.

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Macromolecular X-ray crystallography is an important and powerful technique in drug discovery, used by pharmaceutical companies in the discovery process of new medicines. The detailed analysis of crystal structures of protein-ligand complexes allows the study of the specific interactions of a particular drug with its protein target at the atomic level. It is used to design and improve drugs. The starting point of these studies is the preparation of suitable crystals of complexes with potential ligands, which can be achieved by using different strategies described in this chapter. In addition, an introduction to X-ray crystallography is given, highlighting the fundamental steps necessary to determine the three-dimensional structure of protein-ligand complexes, as well as some of the tools and criteria to validate crystal structures available in databases.

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The measured isothermal charging and discharging currents are analyzed either in terms of polarization mechanisms or in terms of charge injection/extraction at the metal-dielectric interface and the conduction current through the dielectric material. We propose to measure the open-circuit isothermal charging and discharging currents just to overpass the difficulties related to the analysis of the conduction mechanisms through the dielectric materials. Besides a polarization current, there is a current related with charge injection or extraction at the metal-dielectric contact and a reverse current related to the charge trapped into the superficial trap states of the dielectric and that can jump at the interface in a reverse way. By fitting the experimental data, two important parameters can be determined (i) the highest value of the relaxation time for the polarization mechanisms still involved into the transient current and (ii) the height W-0 of the potential barrier at the metal-dielectric interface immediately after the step voltage is applied. Only the initial part of the measured isothermal charging or discharging current can be used to obtain information about the polarization processes. By transforming the time-domain data into the frequency domain, a maximum for the imaginary part of the dielectric permittivity is obtained, in good agreement with the data obtained from AC dielectric measurements and the finally thermally stimulated discharge current measurements. (C) 2009 Elsevier B.V. All rights reserved.

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The two-photon decay of heavy, helium-like ions is investigated based on second-order perturbation theory and Dirac’s relativistic equation. Special attention has been paid to the angular emission of the two photons (i.e., how the angular correlation function depends on the shell structure of the ions in their initial and final states). Moreover, the effects from the (electric and magnetic) nondipole terms in the expansion of the electron-photon interaction are discussed. Detailed calculations have been carried out for the two-photon decay of the 1s2s1S0, 1s2s3S1, and 1s2p3P0 states of helium-like Xe52+, Au77+, and U90+ ions.

The two-photon decay of heavy, helium-like ions is investigated based on second-order perturbation theory and Dirac’s relativistic equation. Special attention has been paid to the angular emission of the two photons (i.e., how the angular correlation function depends on the shell structure of the ions in their initial and final states). Moreover, the effects from the (electric and magnetic) nondipole terms in the expansion of the electron-photon interaction are discussed. Detailed calculations have been carried out for the two-photon decay of the 1s2s1S0, 1s2s3S1, and 1s2p3P0 states of helium-like Xe52+, Au77+, and U90+ ions.

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The physical, chemical and mineralogical characterisation of the ash resulting from a pulp mill boiler was performed in order to investigate the valorisation of this waste material through the production of added-value glassy materials. The ash had a particle size distribution in the range 0.06-53μm, and a high amount of SiO2 (∼82wt%), which was present as quartz. To favour the vitrification of the ash and to obtain a melt with an adequate viscosity to cast into a mould, different amounts of Na2O were added to act as fluxing agent. A batch with 80wt% waste load melted at 1350°C resulting in a homogeneous transparent green-coloured glass with good workability. The characterisation of the produced glass by differential thermal analysis and dilatometry showed that this glass presents a stable thermal behaviour. Standard leaching tests revealed that the concentration of heavy metals in the leaching solution was lower than those allowed by the Normative. As a conclusion, by vitrification of batch compositions with adequate waste load and additive content it is possible to produce an ash-based glass that may be used in similar applications as a conventional silicate glass inclusively as a building ecomaterial. © 2010 Elsevier B.V.

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