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Hybrid materials are being developed to add organic functionalities to inorganic materials. Here, titanium dioxide is modified with organophosphonic acids (PAs). In several applications, the surface properties of the material play a key role in their performance (e.g. separation, sorption, catalysis). Hence, the surface properties of these materials need to be specifically adjusted to meet the requirements of each application (e.g. in membrane separation or chromatography). As the synthesis conditions have an important influence on the obtained surface properties, it is necessary to understand the impact and differences introduced by altering synthesis conditions. Different solvents are being applied for modification, but a comparative study of the impact of this change in environments is missing in literature. Therefore, our aim is to study the impact of concentration, temperature and pH in water and toluene on the properties of TiO 2 modified with propylphosphonic acid (3PA). By combining complementary techniques (DRIFT, TGA and 31 P/CP MAS NMR), clear differences induced by the solvent can be found. Moreover, in toluene a lower concentration of 3PA is required to obtain closed packed monolayers than in water. Furthermore, both solvent and concentration are influencing the modification degree and binding type formed on the surface. Moreover, only in water, next to the concentration, also the temperature and pH have a strong impact on the binding type of 3PA. A clear difference in thermal stability of 70 °C was found between both binding types.

Chemical process installations are exposed to aggressive chemicals and conditions leading to corrosion. The damage from corrosion can lead to an unexpected plant shutdown and to the exposure of people and the environment to chemicals. Due to changes within and on the surface of materials subjected to corrosion, energy is released in the form of acoustic waves. This acoustic activity can be captured and used for corrosion monitoring in chemical process installations. Wavelet packet coefficients extracted from the acoustic activity have been considered to determine whether corrosion occurs, and to identify the type of corrosion process, at least for the most important corrosion processes in the chemical process industry. Feature subset selection is then applied to these wavelet coefficients to achieve a much higher accuracy in the identification of different corrosion processes than when no feature subset selection is applied to the acoustic waves. However, due to the statistical dependencies that potentially exist between the wavelet coefficients, the latter should not be selected independently from each other. Local discriminant basis selection algorithms do not take the statistical dependencies between wavelet coefficients into account. In this paper, we have used several mutual information-based approaches that take these dependencies into account and compared them to the wavelet-specific local discriminant basis selection algorithm. Furthermore, a hybrid filter–wrapper genetic algorithm, which uses a relevance–redundancy approach as a local search procedure, was designed. The highest classification accuracies are obtained with the hybrid filter–wrapper genetic algorithm, for all classifiers used in this paper. Furthermore, the proposed algorithm easily outperformed one of the most commonly used classifiers in chemometrics: partial least squares discriminant analysis (PLS-DA). A naive Bayes classifier that uses the features selected by the hybrid filter–wrapper genetic algorithm was able to identify the absence of corrosion, uniform corrosion, pitting and stress corrosion cracking, with an accuracy of up to 87.20%.

This study addresses the determinants of bankruptcy costs. Prior studies have predominantly focused on the costs of Chapter 11 procedures and have made comparisons with bankruptcy auction systems and Chapter 7 procedures. By examining 289 Dutch bankruptcy cases, this study analyzes what determines the time spent on the winding up of bankruptcy cases, and therefore the costs of winding up bankruptcies. We find relationships between the time spent on the winding up and the type of debtor, size of the assets, assets/debt ratio, presence of fraud, the number of debtors, number of employees, number of creditors, the presence of business activities at the time of the filing, cause for the filing, and the filer for bankruptcy. The results imply, among other things, that in cases of equal complexity, more time is spent on the winding up if (considerable) assets are available than in cases that lack considerable assets. Additionally, we find low remuneration fees for bankruptcy trustees. Compared to minimum fees of lawyers and the estimated standard bankruptcy rate of €119, a mean hourly remuneration of €60.82 is found, with an even lower median figure of €38.40. The results are of importance for reviewing bankruptcy trustees’ fees, for determining if bankruptcy trustees are sufficiently compensated, and for evaluating the system of cross-subsidization in which the hourly rate of the trustee increases if the size of the assets exceeds certain thresholds.

Traces of lead, cadmium, zind and manganese in copper and copper compounds are determined, in some cases simultaneously, by anodic stripping voltammetry on a hanging mercury drop electrode. The four metals are separated from the bulk copper(II) by preliminary electrolysis of the copper matrix at a controlled potential on a platinum cathode. The method is applied to commercially available high-purity copper, showing satisfactory sensitivity and accuracy. The determination limits are about 10 -9 M for lead, 5·10 -10 M for cadmium, 10 -9 M for zinc and 10 -8 M for manganese in solution ; this corresponds, respectively, to 0.01, 0.002, 0.003 and 0.03 p.p.m. for a 0.5-g sample in a final volume of 25 ml after separation. However, because of blank values, the final determination limits are about 0.1 p.p.m. for lead and 0.3 p.p.m. for zinc.