Abstract: The research of soil contamination by heavy metal is an important field due to its environmental and health implications. The goal was to study the elemental mobility as a function of depth. For this reason, the distribution of heavy metals (V, Cr, Co, Ni, Cu, Zn, As, Sn, and Pb) was investigated along soil profiles up to a depth of 15m at 9 sampling sites in the Nilufer industrial district (Bursa, Turkey). Elemental analyses were done with the Epsilon 5 energy dispersive X-ray fluorescence and inductively coupled plasma mass spectrometry equipment. Particle analysis was performed with a JEOL scanning electron microscope equipped with a Si(Li) X-ray detector. The crystallographic compositions of oxide compounds in soil samples were identified by a Rigaku X-ray diffraction instrument. Different parameters such as the soil's chemical (mineralogical structure, pH, and electrical conductivity) and physical properties (the number of blows, the stiffness index, the liquidity index, the plasticity index, and the water content) were analyzed. To assess the mobility of the heavy metals, diffusion (D) and convection coefficients (?) were calculated with the finite difference method. Convection was determined to dominate the studied region. In addition, the mobility coefficient was determined for each metal. High mobilities were determined for Zn and V, moderate mobilities for Cr, Ni, Cu, and As, and low mobilities were determined for Co and Pb. The results revealed that elements had reached depths of up to 15m, causing irreversible soil contamination that may lead to environmental health issues.

Abstract: Several specimens of Libyan desert glass (LDG), an enigmatic natural glass from Egypt, were subjected to investigation by micro-Raman spectroscopy. The spectra of inclusions inside the LDG samples were successfully measured through the layers of glass and the mineral species were identified on this basis. The presence of cristobalite as typical for high-temperature melt products was confirmed, together with co-existing quartz. TiO2 was determined in two polymorphic species rutile and anatase. Micro-Raman spectroscopy proved also the presence of minerals unusual for high-temperature glasses such as anhydrite and aragonite.

Abstract: Tissue engineering combines artificial scaffolds and living cells in order to reconstruct damaged tissues and organs. The biodegradable scaffolds should maintain their mechanical properties during first stages of the regeneration. The aim of this study was to investigate the extent the degradation affects the mechanical stability of novel biodegradable composite scaffolds in relation to their composition. The scaffolds were made using fused deposition modeling. They were composed of ternary composites containing poly(epsilon-caprolactone) (PCL), 5 wt% of tricalcium phosphate (TCP) and 5, 15, and 25 wt% of poly(lactide-co-glycolide) (PLGA). Scaffolds made of pristine PCL and binary composite PCL-TCP were tested as reference samples. The degradation experiment was carried out in simulated body fluid at 37 degrees C for 12 weeks. Mechanical tests were carried out in a mechanical tester. Strain was measured using digital image correlation and crossbar displacement. Chemical composition had a significant effect on initial mechanical properties and their changes during degradation. The initial apparent Young's modulus of ternary composite scaffolds was two times higher than that of PCL-TCP. Higher PLGA concentration yielded faster decrease of the mechanical properties. At the end of the experiment, there were no significant differences of the modulus among all tested materials although degradation of the ternary composite scaffolds was significantly advanced. (C) 2015 Society of Plastics Engineers

Abstract: This study investigates the complex mixture of volatile organic compounds (VOCs) released by and accumulated within a collection of historic medicinal, pharmaceutical, and cosmetic artifacts housed at the National Museum of American History (Smithsonian Institution). In recent years, staff have become concerned, both for the safety of the objects and for personnel working in the collection, about strong unremediated odors accumulating within several storage cabinets. Museum staff also wondered if non-odorous off-gassing might need remediation. Solid-phase microextraction combined with gas chromatography–mass spectrometry analysis (SPME–GC–MS) was used to identify VOCs present in the storage room housing the collection. Over 160 compounds were detected and identified overall. Among these, 49 appeared to be directly related to ingredients used in the manufacture of many collection items. The results of the study suggest that SPME–GC–MS can be a strong tool for the rapid screening of multicomponent museum collections exhibiting off-gassing problems, before the pursuit of other more tedious analytical approaches. Additionally, the study reveals valuable insight into the characteristic volatile emission of historic medicinal, pharmaceutical, and cosmetic artifacts, increasing understanding of, and decision-making for, similar collections of objects. Eventually, it is hoped that this information can be used to inform mitigation strategies for the capture and reduction of VOCs in collections storage areas.

Abstract: Energy-dispersive X-ray fluorescence was used for the analysis of hair samples from three different age groups of the Sudanese population. Hair samples were digested in a mixture of nitric and perchloric acids and the metals were then precipitated with ammonium pyrrolidine dithiocarbamate. The variations of the Fe, Cu, Zn and Pb content of hair with age were investigated. The averages of the elemental concentrations in each age group were compared with the other age groups and with literature values. The correlation of each pair of elements in the hair samples was also investigated.

Abstract: One of the most striking but unexplained phenomena in the natural degradation of glass is the transformation of an almost colorless, transparent and homogeneous glass into a colored, opaque and heterogeneous degradation layer. In many cases, the degradation layer consists of numerous lamellae with a thickness between 0.1 and 10 pm. However, both internal structure and formation proess of laminated degradation layers remain unclear. In this paper, a model is proposed where we assume that transformed (degraded) glass consists of a random packing of nano-sized silica particles while the lamellae are the result of different packing densities. The model is able to connect the texture of numerous lamellae observed by several types of microscopic techniques with the structure at molecular level determined by means of chemical analysis. In addition, the model is able to explain numerous properties such as the parameters responsible for the contrast between lamellae. This contrast can be caused by differences in color, density, elemental composition, or surface roughness. (C) 2016 Elsevier B.V. All rights reserved.

Abstract: A laser microprobe mass analyser and a highly automated electron probe X-ray microanalysis unit have been used to study the elemental composition, inorganic speciation and morphology of atmospheric aerosols collected at various remote to polluted and marine to continental locations.

Abstract: Dit onderzoek presenteert een overzicht van de mogelijkheden van LA-ICP-MS als een techniek voor kwantitatieve analyse, bepalen van isotoopverhoudingen en elementaire beeldvorming. Hiervoor wordt de techniek zelf voorgesteld en worden de belangrijkste parameters die een invloed hebben op de kwaliteit van een LA-ICP-MS meting beschreven. Voor kwantitieve analyse worden de huidige calibratiestrategieën voor LA-ICP-MS toegelicht, zowel op het vlak van selectie en bereiding van standaarden als op het vlak van dataverwerking. Daarnaast werd een nieuwe calibratiestrategie voorgesteld, gebaseerd op een lineaire combinatie van standaarden. Een case study met de traditionele calibratiestrategie uit de literatuur werd uitgevoerd en vergeleken met data van SEM-EDX om een referentiekader te schetsen voor de performantie van de techniek. In een tweede case study werd onze nieuwe calibratiestrategie toegepast en werd er uitsluitend gebruik gemaakt van LA-ICP-MS, wat uitstekende resultaten opleverde. Met het oog op het bepalen van isotoopverhoudingen, werd er onderzocht wat de limieten zijn van het gebruik van een lage resolutie quadrupool massaspectrometer voor deze bepaling. Dit stelde ons in staat om de te verwachten accuraatheid en precisie in te schatten. De performantie bleek goed genoeg te zijn om weapon-grade plutonium te onderscheiden van global fall-out, zoals het werd aangetoond in de case study omtrent dit onderwerp. Uiteindelijk hebben we ook LA-ICP-MS geëvalueerd als een techniek voor elementaire beeldvorming, waarbij we tevens de meest courante multivariate data analyse hebben beschreven. Om de techniek te plaatsen tegenover andere elementaire technieken, werd een historisch verffragment geanalyseerd dat in het verleden reeds geanalyseerd was met SEM-EDX and μ-XRD. Op die manier konden we de resultaten accuraat vergelijken met de andere technieken.