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Now showing items 1 - 11 of 11

  • Unconventional microanalysis for low-Z, volatile and organic aerosol compounds

    Worobiec, A.   De Hoog, J.   Osá   n, J.   Szaló   ki, I.   Joos, P.   Van Grieken, R.  

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  • AIP Conference Proceedings [AIP XXII INTERNATIONAL CONFERENCE ON RAMAN SPECTROSCOPY - Boston (MA) (8–10 August 2010)] - Behavior of Semi-volatile Particles under a Laser and Electron Beam—Influence on the Quality of Analytical Results

    Worobiec, A.   Potgieter-Vermaak, S.   Darchuk, L.   Vishnyakov, V.   Potgieter, H.   Van Grieken, R.   Champion, P. M.   Ziegler, L. D.  

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  • Comparative assessment of air quality in two health resorts using carbon isotopes and palynological analyses RID A-3154-2009

    Gorka, M.   Jedrysek, M. O.   Maj, J.   Worobiec, A.   Buczynska, A.   Stefaniak, E.   Krata, A.   Van Grieken, R.   Zwozdziak, A.   Sowka, I.   Zwozdziak, J.   Lewicka-Szczebak, D.  

    This paper describes results of applying the palynological and carbon isotopic analysis of the organic fraction of Total Suspended Particles (TSP) to discriminate distinct pollution sources and assess the anthropogenic impact for the investigated areas. The samples of atmospheric particles were collected in Czerniawa and Cieplice (two health resorts in Lower Silesia, SW Poland) twice a year in summer and winter season (from July 2006 to February 2008). The palynological spectra represent in the vast majority local plant communities without a noticeable contribution of long-transported plant particles. Palynological analysis revealed also differences in the specificity of the two sampling areas, i.e. the higher contribution of identified organic material in Czerniawa stands for more natural character of this site, but is also responsible for the higher allergic pressure when compared to Cieplice. The carbon isotopic composition of TSP varied seasonally (delta(13)C value from -27.09 parts per thousand in summer to -25.47 parts per thousand in winter). The increased delta(13)C value in winter (heating period) is most probably caused by uncontrolled contribution of coal soot. On the basis of isotopic mass balance the calculated contribution of anthropogenic organic particles in the atmosphere reached in winter season 72% in Czerniawa and 79% in Cieplice. (c) 2008 Elsevier Ltd. All rights reserved.
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  • Damage and molecular changes under a laser beam in SEM-EDX/MRS interface: a case study on iron-rich particles

    Worobiec, A.   Darchuk, L.   Brooker, A.   Potgieter, H.   Van Grieken, R.  

    The control of damage to individual environmental particles by a laser beam during Raman spectroscopy carried out in ambient air is generally well understood. The nature and control of damage under vacuum conditions (e. g. in the scanning electron microscopy with energy X-ray detection combined with micro-Raman spectroscopy - interfaced SEM-EDX/MRS) are more complex and less well comprehended. The physical and chemical processes that affect the damage caused to small particles by lasers still remain somewhat unclear, but certainly the atmosphere (vacuum/air) and the beam intensity have very significant influences. Furthermore, it has been determined that some particles (e. g. haematite), although stable under an electron beam, are damaged by the laser beam, hampering their analysis. Additionally, when simultaneous analyses by SEM/EDX and MRS are considered, the correct choice of the collection surface plays a crucial role. As a result, the following collection substrates were tested to determine their influence on the laser beam damage process to the particle: silver and aluminium foils and silicon wafers. A test study was performed using artificial examples of haematite (Fe(2)O(3)) particles. Exposure of Fe(2)O(3) particles in vacuum to 514- and 785-nm laser radiation often leads to their melting, transformation and evaporation. The dependence of the damage caused by the laser beam on the particle structure is reported here. Molecular and crystallographic changes have also been revealed. Formation of magnetite (as an effect of re-crystallisation) and Raman inactive structures was detected. Copyright (C) 2010 John Wiley & Sons, Ltd.
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  • Size distribution and chemical properties of welding fumes of inhalable particles

    Oprya, M.   Kiro, S.   Worobiec, A.   Horemans, B.   Darchuk, L.   Novakovic, V.   Ennan, A.   Van Grieken, R.  

    The goal of the present study was to analyze the relationship between the fume formation rate, welding conditions, chemical composition of welding fume particles and their size. In the range from 0.25 to 16 mu m aerodynamic diameter, three distinct types of welding fume particles were identified in the welder's breathing zone. The elemental composition of each type depended completely on the used welding materials, and reflects their mechanism of formation. Their relative abundance in the welding fume appeared to be dependent on the electrode coating, as well as the heat input during welding. (C) 2011 Elsevier Ltd. All rights reserved.
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  • Infrared investigation of hard human teeth tissues exposed to various doses of ionizing radiation from the 1986 Chernobyl accident

    Darchuk, L. A.   Zaverbna, L. V.   Bebeshko, V. G.   Worobiec, A.   Stefaniak, E. A.   Van Grieken, R.  

    Infrared spectroscopy (IR) was applied to study changes in solid teeth tissues of persons exposed to low (0.12-0.20 Gy) and high (0.5-1.7 Gy) doses of ionizing radiation during their work in the Chernobyl zone after the accident. Changes in the inorganic and organic matrix of teeth were noted for both high and low radiation doses. The obtained results demonstrated that high doses of radiation lead to imbalance between phosphate-carbonate phases level (because of increasing of CO32- content) and accumulation of soluble phosphates in the mineral part of the teeth. These changes have an effect on dental matrix strength. Low doses of radiation do not induce appreciable negative changes in the mineral part of all tooth tissues but lead to changes in organic matrix of teeth (in collagen). The present results demonstrated that pathological effect of radiation touches upon all dental tissue and obviously all bone systems of irradiated people.
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  • Molecular and elemental characterisation of mineral particles by means of parallel micro-Raman spectrometry and scanning electron microscopy/energy dispersive X-ray analysis

    Stefaniak, E. A.   Worobiec, A.   Potgieter-Vermaak, S.   Alsecz, A.   Torok, S.   Van Grieken, R.  

    The "fingerprinting" of a molecular structure obtained by micro-Raman spectroscopy (MRS) can be successfully complemented by means of X-ray spot analysis through the application of scanning electron microscopy equipped with an X-ray detector (SEM/EDX). The elemental composition revealed by SEM/EDX is essential for a correct interpretation of the collected Raman spectra. The results presented here illustrate how the two techniques can be combined to characterize geological samples, especially in the case of individual particles. The samples involved in the experiments were Zr- and Ti-bearing sand from South Africa (with major minerals such as zircon and rutile) and U mine tailings from Hungary (rich with feldspars, quartz and sulphate minerals). Mineral phases detected by MRS were identified according to their respective main Raman shifts, with a spatial resolution up to 1 mu m, depending on the parameters set. Some unusual and sometimes inexplicable Raman activity was observed, which was ascribed to and rationalized by the presence of accompanying elements as detected with EDX. The relocation of a particle by means of the two instruments was facilitated with TEM grids. Although the limitations of the sequential use of SEM/EDX and MRS, such as different beam sizes, probing depth and surface topography, should be considered in their application to the analysis of individual geological particles, the two methods appeared to be complementary. Not only do they provide correlated chemical information about the sample, but also enable chemical characterization that would be otherwise incomplete when analyzed on a stand-alone basis. (c) 2006 Elsevier B.V. All rights reserved.
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  • Behavior of Semi-volatile Particles under a Laser and Electron Beam - Influence on the Quality of Analytical Results

    Worobiec, A.   Potgieter-Vermaak, S.   Darchuk, L.   Vishnyakov, V.   Potgieter, H.   Van Grieken, R.  

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  • Structural features of human tooth tissues affected by high dose of external ionizing radiation after nuclear catastrophe of Chernobyl plant

    Zaverbna, L. V.   Worobiec, A.   Van Grieken, R.  

    The application of micro-Raman spectroscopy is discussed for the analysis of structural features of human tooth tissues affected by high doses of external ionizing radiation (0.5-1.7 Gy) after the nuclear plant catastrophe in Chernobyl in 1986. The results have shown significant changes in the mineral matrix of dental enamel that lead to the decrease of tooth enamel hardness. Destruction of the collagen chain of the organic matrix has been observed for dentin and cementum. (C) 2010 Elsevier B.V. All rights reserved.
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  • Particulate ba-barite and acantharians in the southern ocean during the European iron fertilization experiment (EIFEX) RID B-5958-2008

    Jacquet, S. H. M.   Henjes, J.   Dehairs, F.   Worobiec, A.   Savoye, N.   Cardinal, D.  

    Particulate biogenic Ba, Sr and Ca and barite crystal contents from suspended matter were compared with acantharian water column distributions and individual Ba/Sr acantharian skeletal ratios during the European Iron Fertilization Experiment (EIFEX) in the Southern Ocean. In the upper 150 m, results indicate that the particulate biogenic Ba-xs signal is almost free of barite ( BaSO4) particles and follows the same evolution as biomass parameters, implying that Ba is incorporated into or adsorbed onto biologically derived ( biogenic) particles of which acantharians could account nearly the whole surface Ba-xs signal. In contrast, in the mesopelagic zone ( 150 - 1000 m), particulate biogenic Ba-xs is mainly composed of micro-crystalline barite. Calculations indicate that the combined acantharian associated Ba contents in the upper 150 m and between 150 - 500 m, if entirely transformed into barite, an unlikely condition, and dispersed in the 150 - 1000 m layer, could explain up to 20% of the mesopelagic Ba-xs contents. Our results thus indicate that acantharians are probably not the major source of particulate Ba-barite in the water column. They support the hypothesis that mesopelagic Ba-xs is mostly built-up as the result of biogeochemical processes within aggregates and its usefulness as a proxy of mesopelagic C remineralization.
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  • Composition of prehistoric rock-painting pigments from Egypt (Gilf Kebir area)

    Darchuk, L.   Rotondo, G. Gatto   Swaenen, M.   Worobiec, A.   Tsybrii, Z.   Makarovska, Y.   Van Grieken, R.  

    The composition of rock-painting pigments from Egypt (Gilf Kebia area) has been analyzed by means of molecular spectroscopy such as Fourier transform infrared and micro-Raman spectroscopy and scanning electron microscopy coupled to an energy dispersive X-ray spectrometer and X-ray fluorescence analysis. Red and yellow pigments were recognized as red and yellow ochre with additional rutile. (C) 2011 Elsevier B.V. All rights reserved.
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