Research Anna Worobiec

Abstract

In frame of the following research project, the existing micro and trace analytical techniques such as electron probe X-ray microanalysis (EPMA), micro-Raman spectroscopy (MRS) and energy dispersive X-ray fluorescence (EDXRF) will be optimized in order to obtain the most relevant information necessary for the determination of the weathering of the art objects, preservation techniques and the optimization of the so-called "preventive conservation" of the cultural heritage."

Researcher(s)

• Promoter: Van Grieken Rene
• Co-promoter: Worobiec Anna
• Fellow: Krupinska Barbara

Research team(s)

Project type(s)

• Research Project

Abstract

In frame of the following research project, the existing micro and trace analytical techniques such as electron probe X-ray microanalysis (EPMA), micro-Raman spectroscopy (MRS) and energy dispersive X-ray fluorescence (EDXRF) will be optimized in order to obtain the most relevant information necessary for the determination of the weathering of the art objects, preservation techniques and the optimization of the so-called "preventive conservation" of the cultural heritage."

Researcher(s)

• Promoter: Van Grieken Rene
• Co-promoter: Worobiec Anna
• Fellow: Krupinska Barbara

Research team(s)

Project type(s)

• Research Project

Abstract

At present, the direct radiation exposure to the environment from the Chernobyl IV plant, which exploded in 1986, has been reduced significantly due to radioactive decay. However, the molten fuel material within the concrete shelter, the so-called 'Sarcophagus', is continuously releasing atmospheric aerosols. These aerosols might at present constitute the major hazard from Chernobyl, not only locally but also over distances of many hundreds of km. All this depends on the physical and chemical properties of the emanating aerosols.

Researcher(s)

• Promoter: Worobiec Anna

Research team(s)

Project type(s)

• Research Project

Abstract

The ultimate goal of the post-doc research will be the further optimisation of the measurements strategy with the "thin window" Electron Probe X-rays Microanalysis (EPMA) and micro-Raman Spectrometry (MRS), tested in the passed previous years. The instruments will be used both independently and in the interfaced mode. This innovative application will be studied oriented with respect to both chemical composition and physical and structural characterisation of natural and anthropogenic environmental particles. The attention will also be paid to interpretation of the data from both techniques.

Researcher(s)

• Promoter: Van Grieken Rene
• Fellow: Worobiec Anna

Research team(s)

Project type(s)

• Research Project

Abstract

The combination of the micro-Raman spectrometry (RMS) and "thin window " electron probe X-Ray Micro Analysis (TW-EPMA) for environmental research is able to give detailed information about the chemical characteristics of individual particles. The aim of this application is to generate as much as possible elemental and molecular information from the same particle. However, the combined use of EPMA and MRS methods meets fundamental difficulties, in particular the sensitivity of environmental particles under the laser beam and electron beam irradiation.

Researcher(s)

• Promoter: Worobiec Anna

Research team(s)

Project type(s)

• Research Project

Abstract

Hardly any research has been done on indoor air quality in offices, schools and residences in Belgium, while industrial occupational exposure has been documented much better for some pollutants. This study will include systematically the determination of the levels and chemical composition of the fine and ultra-fine particulate fractions and of health-related pollution gases, in numerous and diverse indoor environments in the Province of Antwerp.

Researcher(s)

• Promoter: Van Grieken Rene
• Co-promoter: Worobiec Anna

Research team(s)

Project type(s)

• Research Project

Abstract

The aim of this project is to investigate physical and chemical properties of atmospheric aerosols in the selected health resorts of Lower Silesia, located in the Polish part of the "Black Triangle". The field of investigation involves morphology and elemental analysis of individual dust particles by means of scanning electron microscope equipped with X-ray detector (SEM/EDS), automated electron probe X-ray microanalysis (EPMA), quantitative bulk analysis of suspended particulate matter by means of X-ray fluorescence spectrometry (EDXRF) and application of micro-Raman spectroscopy to determine its molecular composition. Additionally, a method of stable isotope analysis will be developed to be suitable for dust particles passively and dynamically sampled. Monitoring of gaseous pollutants will be enhanced by the determination of light organic compounds with passive sampling applied. The obtained results will be applied to create theoretical basis and estimation of the observed correlations and statistical modeling.

Researcher(s)

• Promoter: Van Grieken Rene
• Co-promoter: Worobiec Anna

Research team(s)

Project type(s)

• Research Project

Abstract

To optimise the effective trapping of welding particles, their chemical composition and morphology need to be determined. Electron Probe X-Ray Microanalysis (EPMA) has been used successfully to characterize individual aerosol particles in an automated way, and can give detailed information about their elemental composition, size distribution and morphology. The application of µ-Raman Spectrometry in conjunction with the EPMA/EDX creates the possibility to further characterize the particles as far as their molecular composition is concerned.

Researcher(s)

• Promoter: Worobiec Anna

Research team(s)

Project type(s)

• Research Project

Abstract

The study of atmospheric aerosols has recently become very important for two major reasons: the small particle size fraction has a very important influence on human health and it affects the global climate. Micro-analytical characterization of individual particles generally permits more information to be obtained than is feasible with bulk analysis. The development of thin-window energy-dispersive detectors was of major importance for electron probe microanalysis (EPMA), in order to detect light elements (6<Z). This technique has proven to be a powerful tool for the study of individual particles, because the combination of electron microscopic imaging with energy dispersive X-ray detection allows characterizing large numbers of individual particles in a fast, automated way. The improved technology largely extended our knowledge on atmospheric reactions, due to novel information obtained on the chemical composition and reactions of aerosol particles. The combination of computer-controlled single-particle analysis using thin-window EPMA and a reverse Monte Carlo quantification procedure proved to be very beneficial for providing elemental concentrations within 15 % relative accuracy, also for low-Z elements. Beam-sensitive particles such as ammonium sulphate and nitrate can be analysed by using a liquid-nitrogen cooled sample stage. Additionally, the automation gives the possibility to analyse huge numbers of aerosols at a single particle level, giving better statistical results. Further developments of this methodology should allow studying surface layers on individual microscopic particles. Recently, some surface layers on so-called Asian dust particles were studied, i.e. soil dust, which is transported from the Gobi desert during certain periods of the year and influences the regional weather and air pollution considerably. In order to obtain more detailed information about the speciation of the individual environmental particles, it is proposed that different combinations of microanalysis techniques should be studied as well. The combination of the micro-Raman technique and TW-EPMA for environmental research can give detailed information about the characterisation of individual particles, which permits better characterization and provide more complete information about the Global Change problems, pollution sources and their processes. Micro-Raman spectroscopy has rather unexplored potentials in the single particle analysis field, particularly if it can be coupled with EPMA.

Researcher(s)

• Promoter: Van Grieken Rene
• Fellow: Worobiec Anna

Research team(s)

Project type(s)

• Research Project