6th European Pulse Plating Seminar

Over the past decade the European Pulse Plating Seminar has been established as the most important event for discussing research and applications of pulse plating. Now it is organised every second year in the area of Vienna by the company Happy Plating. For the past two years it has been co-organised with the European Academy of Surface Technology, EAST. The pulse plating seminars have made it possible to follow how the application of pulse plating has increased and widened during the last decade since the first seminar in 2006.     

Robust design of a shape memory actuator with slider and slot layout and passive cooling control

Microsystem Technologies - This work proposes a new shape memory actuator based on a slider and slot mechanism. The device is composed by two couples of opposed SMA coil elements. The SMA elements...     

Environmental impact of poultry production systems on surface water: monitoring the Taquari-Antas basin,southern Brazil

ABSTRACT

The research evaluated the impact of poultry farming on the quality of surface waters in a mountainous area of southern Brazil, in order to collect data and assist in the decision-making for sustainable development. The study monitored 13 spots for two years in the sub-basins with intense poultry activity. The water samples were submitted to physicochemical and microbiological analyses in order to assess the Water Quality Index (WQI). The data were analysed by principal component analysis and Pearson’s correlation. Some zones are able to receive future investments and could serve as a basis for the installation of new agricultural units. Others require greater attention from the environmental control agencies.     

The influence of API concentration on the roller compaction process: modeling and prediction of the post compacted ribbon,granule and tablet properties using multivariate data analysis

Objective: While previous research has demonstrated roller compaction operating parameters strongly influence the properties of the final product, a greater emphasis might be placed on the raw material attributes of the formulation. There were two main objectives to this study. First, to assess the effects of different process variables on the properties of the obtained ribbons and downstream granules produced from the rolled compacted ribbons. Second, was to establish if models obtained with formulations of one active pharmaceutical ingredient (API) could predict the properties of similar formulations in terms of the excipients used, but with a different API.

Materials and methods: Tolmetin and acetaminophen, chosen for their different compaction properties, were roller compacted on Fitzpatrick roller compactor using the same formulation. Models created using tolmetin and tested using acetaminophen. The physical properties of the blends, ribbon, granule and tablet were characterized. Multivariate analysis using partial least squares was used to analyze all data.

Results: Multivariate models showed that the operating parameters and raw material attributes were essential in the prediction of ribbon porosity and post-milled particle size. The post compacted ribbon and granule attributes also significantly contributed to the prediction of the tablet tensile strength.

Conclusions: Models derived using tolmetin could reasonably predict the ribbon porosity of a second API. After further processing, the post-milled ribbon and granules properties, rather than the physical attributes of the formulation were needed to predict downstream tablet properties. An understanding of the percolation threshold of the formulation significantly improved the predictive ability of the models.     

Comparative Study of the Adsorption Thermodynamic Parameters Estimated through Different Approaches

The equilibrium constant （K0）, change in free energy （△G）, enthalpy （△H） and entropy （△S） of ammonium adsorption by a Cuban natural zeolite were estimated at the temperatures of 25, 35, 45 and 55℃ using extensively used approaches. Equilibrium data were obtained in the concentration range 50-1,200 mg·L-1 of ammonium and used in the estimation of thermodynamic parameters. Freundlich＇s isotherm model was found as with the best adjustment to equilibrium data at 25, 45 and 55℃, whereas, Redlich-Peterson＇s model had a better performance at 35 ℃. A discontinuous and unusual behavior was observed on adsorption capacity of the zeolite, with an increase from 25 ℃ to 35 ℃ followed by a decrease from 35℃ to 55 ℃. K0 values presented differences that reached up to 105 from one methodology to other. Depending on the method considered, AS results indicated both increase or decrease in system degree of disorder and △G indicated both physisorption or chemisorption process, proving the poor correlation between the estimation proceedings of such important data. The results from Gaines and Thomas method were recognized as the most correlated to calorimetric studies, as well as to equilibrium data and observations related to system entropy.     

Molecular self-assembly at solid surfaces

Self-assembly, the process by which objects initially distributed at random arrange into well-defined patterns exclusively due to their local mutual interactions without external intervention, is generally accepted to be the most promising method for large-scale fabrication of functional nanostructures. In particular, the ordering of molecular building-blocks deposited at solid surfaces is relevant for the performance of many organic electronic and optoelectronic devices, such as organic field-effect transistors (OFETs), organic light-emitting diodes (OLEDs) or photovoltaic solar cells. However, the fundamental knowledge on the nature and strength of the intermolecular and molecule-substrate interactions that govern the ordering of molecular adsorbates is, in many cases, rather scarce. In most cases, the structure and morphology of the organic-metal interface is not known and it is just assumed to be the same as in the bulk, thereby implicitly neglecting the role of the surface on the assembly. However, this approximation is usually not correct, and the evidence gathered over the last decades points towards an active role of the surface in the assembly, leading to self-assembled structures that only in a few occasions can be understood by considering just intermolecular interactions in solid or gas phases. In this work we review several examples from our recent research demonstrating the apparently endless variety of ways in which the surface might affect the assembly of organic adsorbates.