Research Piet Van Espen

Abstract

This project represents a formal research agreement between UA and on the other hand VLIR. UA provides VLIR research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Examination of instrumental parameters and current validation for the studied heavy metals in order to determine whether the sensitivity of the present apparatus can still be improved. Investigation into the cause of the large deviation between the ICP-MS and XRF results, in particular, for the element antimony (Sb). Investigation of different types of filters for sampling heavy metals. Optimization of XRF devices for elemental analysis, especially in terms of the projects on chemical characterization. This concerns the following elements: Al, As, Ba, Ca, Cd, Cr, Cu, Fe, K, Mn, Mo, Ni, Pb, Sb, Ti, V and Zn.

Researcher(s)

• Promoter: De Wael Karolien
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet
• Co-promoter: Van Grieken Rene

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the IAEA. UA provides the IAEA research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The study of surfaces, interfaces, microscopic and even nanoscopic structures becomes more and more important in the characterization of very diverse materials in metallurgy, microelectronics, optoelectronics, photographic sciences etc. This characterization is mostly carried out using so-called (micro)beam techniques. By interaction of a "primary" beam (electrons, photons, ions), "secondary" signals are generated at the material's surface (electrons, photons, ions, neutrals), which contain information on the composition and/or structure of the material's surface. The various techniques differ in the kind of information, i.e. information depth, depth resolution, possibility to measure depth profiles, lateral resolution, compatibility with certain types of materials (electrical insulator vs. conductor, refractory vs. labile material), destructive or non-destructive character and type of information (elemental, istopic, molecular) It is clear that one method cannot answer all questions. Moreover, the required equipment is very expensive It is not possible for one research group to have in-house all infrastructure, accessories, know-how, know-why, and experienced personnel. Cooperation is therefore a must. The scientific research community aims at facilitating mutual consultations, exchanges and access to complementary equipment for solving a variety of problems, introduced by one or more of its members.

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

This is a fundamental research project financed by the Research Foundation - Flanders (FWO). The project was subsidized after selection by the FWO-expert panel.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is to determine the possibility in improving the quality of radiographic images acquired from 18-20th century paintings. For this, we are looking for methods that are able to detect small absorption contrast differences that remained invisible so far.

Researcher(s)

• Promoter: Van Espen Piet
• Co-principal investigator: Schalm Olivier

Research team(s)

Project type(s)

• Research Project

Abstract

This project represents a formal research agreement between UA and on the other hand the Flemish Public Service. UA provides the Flemish Public Service research results mentioned in the title of the project under the conditions as stipulated in this contract.

Researcher(s)

• Promoter: Van Espen Piet
• Promoter: Van Grieken Rene
• Co-promoter: Van Meel Katleen

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Serneels Sven

Research team(s)

Project type(s)

• Research Project

Abstract

The composition of rolling emulsions varies throughout the production process. Since the exact composition at a certain time is unknown, it is nearly impossible to provide standard solutions in the laboratory. Hence, in this work, emulsions emerging from the process stream are quantified by dint of the generalized standard additions method (GSAM). These solutions are then used as standards for calibration, which is being done by means of partial least squares regression (PLS). Albeit this technique has become a standard routine in many a laboratory, its theoretical aspects remain mostly unknown. In this work, these theoretical aspects are investigated and elucidated, which leads to the construction of more realistic sample specific prediction intervals, as well as to a more robust method.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Serneels Sven

Research team(s)

Project type(s)

• Research Project

Abstract

The composition of rolling emulsions varies throughout the production process. Since the exact composition at a certain time is unknown, it is nearly impossible to provide standard solutions in the laboratory. Hence, in this work, emulsions emerging from the process stream are quantified by dint of the generalized standard additions method (GSAM). These solutions are then used as standards for calibration, which is being done by means of partial least squares regression (PLS). Albeit this technique has become a standard routine in many a laboratory, its theoretical aspects remain mostly unknown. In this work, these theoretical aspects are investigated and elucidated, which leads to the construction of more realistic sample specific prediction intervals, as well as to a more robust method.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Serneels Sven

Research team(s)

Project type(s)

• Research Project

Abstract

This project aims at the optimisation of the methodology of the simultaneous determination of the electronic and atomic structure and the chemical composition and speciation of nano configurations in a single instrument. The required instrumentation is already available at EMAT (Electron Microscopy for Materials Research) within two different electron microscopes, but the optimal registration of the data and the interpretation of the results still require an integrated effort from various research areas. The above-mentioned nano-structural aspects are of utmost importance for the physical and chemical properties of many materials rendering this fundamental research project a gateway to several novel technological applications. The data sets that will be treated will be acquired using two high resolution transmission electron microscopes (HRTEM) (3000F ARP, CM30 UT), equipped with a field emission gun (FEG) and an electron energy loss spectrometer (EELS) with an energy filter (EF) and CCD detector. The first instrument also has a high resolution scanning transmission unit (STEM) and energy dispersive X-ray detector (EDX). Both instruments provide the possibility to work in nanoprobe, by which spectroscopic information of extremely small volumes can be obtained. The emphasis of the present project is on the optimisation of the acquiring and interpretation of EELS results in combination with other techniques. The fine structure of the spectra can give information on the chemical state and environment enabling the so-called speciation of the elements. In order to reach the extreme detail aimed for, the working conditions of both instruments have to be secured to minimise external influences. The possibility to record the information directly in a digital way via different detectors and CCD cameras implies a strongly enhanced and useful quantitative output. To make this project feasible and successful different domains of expertise available at the UA are brought together: HRTEM and EELS detection (EMAT) and interpretation with respect to chemical speciation (MiTAC) for materials science and the research of image and data improvement (Visielab). In the framework of this project three model systems will be investigated with the objective of optimising the performance of the various possibilities of the instrumentation. Apart from the structural characterisation, particular attention will be paid to the EELS methodology from which chemical as well as electronic information can be extracted. As a first system thin films of La1-xSr xMnO3 (CMR : Colossal Magnetic Resistance)-material in which various valency-states of Mn-ions can disintegrate on a nanometer scale will be examined. This demixing can only be visualised by the differences in the fine-structure of the EELS-spectra (ELNES) of the different states. A second system concerns diamond-like carbon films (DLC) produced by plasma enhanced chemical vapour deposition (PE-CVD). In these films one wants to discriminate the different types of carbon bonds depending on the plasma conditions. Again, especially ELNES will provide the necessary information. In the third model system nanoprecipitates in a known silicon or germanium matrix will be characterised. These precipitates are known from high resolution studies in EMAT but the structure and contents could up to now not unambiguously be determined because no chemical information, e.g. on the presence of oxygen, was available at the required nanoscale. Again the nanoprobe EELS-data should supply the required information for a thorough structure analysis including the speciation of the elements. In a later stage of the project the developed methods and acquired know-how will open possibilities for the study of nano-configurations and interfaces in materials which are more complex than the chosen model systems.

Researcher(s)

• Promoter: Schryvers Nick
• Co-promoter: Scheunders Paul
• Co-promoter: Van Espen Piet
• Co-promoter: Van Landuyt Joseph

Research team(s)

• Electron microscopy for materials research (EMAT)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Methodological of instrumental micro- and trace analytical techniques with emphasis on computer applications and chemometrics : image processing, multivariate methods and software development.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Quantitative analysis using energy-dispersive X-ray fluorescence is hampered by spectral interference and matrix effects. Using the multivariate Partial Least Squares (PLS) method an alternative quantisation procedure is developed that handles those two problems in one step. Monte Carlo simulation is used to generate spectra of standards that are used for building the PLS calibration model. In this way a large variety of materials can be analyzed without operator intervention. This development is especially interesting for on-line and in-field applications of (portable) XRF equipment.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Lemberge Pascal

Research team(s)

Project type(s)

• Research Project

Abstract

Conversion layers on aluminum are used to tailor the surface properties of this material, e.g. for corrosion protection and adhesion. The composition and structure of these conversion layers is however still not well known. Electron microprobe X-ray analysis (SEM-EDX) static secondary ion mass spectrometry (SIMS) and Laser microprobe mass spectrometry are used to obtain information on the elemental and molecular composition (i.e. concentration, lateral and in depth distribution) of these layers at the manometer scale.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Cuynen Erik

Research team(s)

Project type(s)

• Research Project

Abstract

Quantitative analysis using energy-dispersive X-ray fluorescence is hampered by spectral interference and matrix effects. Using the multivariate Partial Least Squares (PLS) method an alternative quantisation procedure is developed that handles those two problems in one step. Monte Carlo simulation is used to generate spectra of standards that are used for building the PLS calibration model. In this way a large variety of materials can be analyzed without operator intervention. This development is especially interesting for on-line and in-field applications of (portable) XRF equipment.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Lemberge Pascal

Research team(s)

Project type(s)

• Research Project

Abstract

WinAxil is a Windows 95 and Windows NT application for the analysis of energy dispersive X-ray spectra. It is based on a non-linear least squares algorithm. The software is developed using Visual C++ and Visual Basic. Quantitative analysis is implemented via a fundamental parameter procedure. WinAxil is applicable for the interpretation of X- ray spectra originating from a variety of excitation modes: tube, seconde target, radio- isotopes, total reflection, synchrotron radiation, electrons (SEM-EDX) and charged particles (PIXE) X-rays.

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The project aims via the use of the most appropriate surface analytical techniques, to fully characterize the aluminium surface and to correlate these characteristics with the production process variables. This will result in a model for predicting the quality.

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The project is involved with getting experience in the use of synchrotron radiation induced X-ray fluoresce by means of the facilities in Daresbury, Hamburg and Paris. Emphasis will be placed on the microscopical imaging capabilities of this technique. Also, the construction of instrumentation for use in Hamburg is part of the project

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Methodological of instrumental micro- and trace analytical techniques with emphasis on computer applications and chemometrics : image processing, multivariate methods and software development.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Conversion layers on aluminum are used to tailor the surface properties of this material, e.g. for corrosion protection and adhesion. The composition and structure of these conversion layers is however still not well known. Electron microprobe X-ray analysis (SEM-EDX) static secondary ion mass spectrometry (SIMS) and Laser microprobe mass spectrometry are used to obtain information on the elemental and molecular composition (i.e. concentration, lateral and in depth distribution) of these layers at the manometer scale.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Cuynen Erik

Research team(s)

Project type(s)

• Research Project

Abstract

This project aims the further development of chemometrics as a scientific discipline. In chemometrics mathematical and statistical techniques, e.g. pattern recognition' experimental design multivariate and robust statistics, are used to selectively extract information from chemical measurements. The collaboration emphasizes on the exchange of knowledge, software and data and on the participation of local and foreign experts in common projects.

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

European Synchrotron Radiation facility (ESRF, Grenoble) will be used for microscopical analysis and characterization using methods such as X-ray fluorescence analysis, fluorescence EXAFS and X-ray microtomography.

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The project deals with the optimisation of x-ray fluorescence spectrometer with respect to excitation and detection geometry and excitation conditions for microscopic x-ray fluorescence. Both the cases of conventional XRF as synchrotron radiation induced XRF are treated.

Researcher(s)

• Promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The project aims via the use of the most appropriate surface analytical techniques, to fully characterize the aluminium surface and to correlate these characteristics with the production process variables. This will result in a model for predicting the quality.

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The quantitative analysis of trace elements in steel and other metal alloys is developped using glow discharge mass spectrometry.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Jonkers Chantal

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Dyck Dirk
• Co-promoter: Dommisse Roger
• Co-promoter: Jacob Willem
• Co-promoter: Lowen Bob
• Co-promoter: Raman Erik
• Co-promoter: Rousseeuw Peter
• Co-promoter: Van Espen Piet
• Co-promoter: Van Landuyt Joseph
• Co-promoter: Verschoren Alain

Research team(s)

Project type(s)

• Research Project

Abstract

The quantitative analysis of trace elements in steel and other metal alloys is developped using glow discharge mass spectrometry.

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Jonkers Chantal

Research team(s)

Project type(s)

• Research Project

Abstract

The project is involved with getting experience in the use of synchrotron radiation induced X-ray fluorescence by means of the facilities in Daresbury, Hamburg and Paris. Emphasis will be placed on the microscopical imaging capabilities of this technique. Also, the construction of instrumentation for use in Hamburg is part of the project.

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Multivariate statistical methods are used to study various aspects of quality control and quality assurance in analytical chemistry.

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

The changing topography of non-flat specimens under ion bombardment complicates the interpretation of SIMS depth profiles. Using image analysis and comparison of electron microscopic images after bombardment, the potential and limitations of very localized depth profiling will be investigated.

Researcher(s)

• Promoter: Gijbels Renaat
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Surface and micro-analytical techniques provide information about the chemical structure of materials in the form of images. These spectroscopic images are processed with multi-variate statistical methods such as PCA and PLS.

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Adams Freddy
• Fellow: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

see abstract

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Jonkers Chantal

Research team(s)

Project type(s)

• Research Project

Abstract

The project is involved with getting experience in the use of synchrotron radiation induced X-ray fluoresce by means of the facilities in Daresbury, Hamburg and Paris. Emphasis will be placed on the microscopical imaging capabilities of this technique. Also, the construction of instrumentation for use in Hamburg is part of the project

Researcher(s)

• Promoter: Adams Freddy
• Co-promoter: Janssens Koen
• Co-promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Jonkers Chantal

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet
• Fellow: Van Puymbroeck Jan

Research team(s)

Project type(s)

• Research Project

Abstract

Researcher(s)

• Promoter: Van Espen Piet

Research team(s)

Project type(s)

• Research Project