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X-ray luminescence computed tomography (XLCT) is a hybrid molecular imaging modality with the merits of both x-ray imaging (high spatial resolution) and optical imaging (high sensitivity to trace nanophosphors). Narrow x-ray beam based XLCT imaging has shown promise for both the high spatial resolution of X-ray imaging and high molecular sensitivity of optical imaging. However, its slow scan speed limits its applications for in vivo and three-dimensional imaging. We have improved the imaging speed of the pencil beam based XLCT by introducing a fly-scanning scheme. In the fly-scanning scheme, the main factor limiting the scanning speed is the data acquisition time at each interval position. To further increase the imaging speed, we used a gated photon counter (SR400, Stanford Research Systems) to replace the high-speed oscilloscope (MDO3104, Tektronix) to acquire measurement data. The photon counter records much less data without losing acquired signals (the peaks). We have achieved 43 seconds per transverse scan, which is 28.6 times faster than before without compromising the XLCT image quality. To perform quantitative study of pencil beam XLCT in imaging x-ray excitable nanophosphor targets in deep scattering media, we then have scanned a cylindrical agar phantom containing twelve targets filled in with three different phosphor concentrations (2.5 mg/ml, 5 mg/ml, and 10 mg/ml) using an upgraded XLCT imaging system in our laboratory. We have, for the first time, quantitatively analyzed the reconstructed phosphor concentrations of deep targets of pencil beam XLCT and evaluated the performance of filtered back-projection (FBP) algorithm using setups of one, two, and four detectors. Then we have scanned phantoms with 3D printed targets and obtain 3D functional images and 3D structural images simultaneously. Then, based on all the work we have done in XLCT imaging, we have designed, built and developed a first-of-its-kind three-dimensional focused X-ray luminescence tomography (FXLT) imaging system for small animals. There is a co-registered microCT imaging system using a cone beam X-ray tube. We are able to perform both FXLT imaging and a pencil beam based microCT using the superfine focused X-ray tube. The system is specially designed for in vivo imaging of small animals. All the major devices rotate on a powerful rotary gantry while the small animals lie down and keep stationary on a linear stage. We developed a lab-made C++ program to control and automate all data acquisition. We applied a high scanning speed method to obtain high-resolution 3D XLCT images in a reasonable time. To evaluate the performance of the FXLT system, we performed both 2D phantom experiments and 3D phantom experiments and achieved good DICE coefficient. In the end, we have performed mice experiments using the proposed FXLT imaging system. We first have scanned two euthanized nude mice with glass capillary tube targets of different sizes filled with phosphor particles. Then we scanned a live nude mouse with two xenografted tumors for in vivo imaging at four different transverse slices. Before scanning, for each tumor, we intratumorally administrated 0.1 mL of nanoparticle Gd2O2S:Eu3+ solution at a concentration of 1 mg/mL. After the in vivo experiment, the mouse was euthanized. Then, we performed a 10-slice FXLT scan of the euthanized mouse. After all the scans were finished, the tumors were sliced and imaged with an electron-multiplying charged coupled device (EMCCD) camera when excited by a cone beam X-ray tube. Finally, the tumor slices were also scanned by an optical microscope for cross validation. We have, for the first time, reconstructed 3D in vivo XLCT images of nanoparticles at superhigh resolution, which demonstrated that the FXLT system is a power tool in molecular imaging and has the capabilities of performing in vivo and 3D imaging for small animals.

This study explores the application of machine learning algorithms for mineral recognition and the identification of planetary materials, using X-ray fluorescence (XRF) spectral measurements. Various machine learning models were trained and evaluated to predict both the elemental abundances of analyzed minerals and the respective mineral species. Convolutional Neural Networks (CNNs) and Support Vector Machines (SVMs) emerged as promising algorithms for both tasks, yielding satisfactory results. Due to resource and time constraints associated with acquiring real-sample measurements, synthetic XRF spectra were employed. These synthetic spectra were generated using Monte Carlo simulations and served as training data for the models, which were subsequently tested on real-sample measurements. Encouraging cross-validation results were obtained, with the trained models demonstrating the ability to detect the presence of elements with an accuracy close to 95%, accompanied by a mean absolute error of 3.42 weight %. Furthermore, a balanced classification accuracy of 78.3% was achieved across 22 mineral classes. These findings highlight the potential of machine learning models to predict characteristic information such as mineral classes and elemental abundances, even when trained only on synthetic data. When combined with other spectroscopic methods, XRF analysis is promising for enhancing existing classifiers., Denna studie utforskar tillämpningen av maskininlärningsalgoritmer för mineraligenkänning och identifiering av planetära material, med hjälp av spektralmätningar baserade på röntgenfluorescens (XRF) . Olika maskininlärningsmodeller tränades och utvärderades för att förutsäga både andelen av olika grundämnen i analyserade mineral och de respektive mineralslagen. Konvolutionella neurala nätverk (CNN) och Support Vector Machines (SVM) visade sig vara lovande algoritmer för båda uppgifterna och gav tillfredsställande resultat. På grund av resurs- och tidsbegränsningar med att erhålla verkliga provmätningar användes syntetiska XRF-spektra. Dessa syntetiska spektra genererades med hjälp av Monte Carlo-simuleringar och användes som träningsdata för modellerna, som därefter testades på mätningar från verkliga mineralprover. Uppmuntrande resultat erhölls vid korsvalidering, där de tränade modellerna detekterade förekomsten av element med en noggrannhet nära 95%, åtföljd av ett medelabsolutfel på 3,42 viktprocent. Dessutom uppnåddes en balanserad klassificeringsnoggrannhet på 78,3% över 22 mineralgrupper. Dessa resultat lyfter fram potentialen hos maskininlärningsmodeller att förutsäga karakteristisk information såsom mineralgrupper och innehåll av grundämnen, även när de endast tränats på syntetiska data. I kombination med med andra spektroskopiska metoder är XRF-analys lovande för att förbättra befintliga klassificeringsmodeller., Cette étude explore ’lapplication ’dalgorithmes ’dapprentissage automatique pour la reconnaissance des minéraux et ’lidentification de matériaux planétaires, en utilisant des spectres de fluorescence des rayons X (XRF). Divers modèles ’dapprentissage automatique ont été entrainés et évalués pour prédire à la fois ’labondance des éléments chimiques constituants les minéraux analysés et les espèces minérales. Les réseaux de neurones à convolution (CNNs) et les machines à vecteurs de support (SVMs) ressortent comme des algorithmes prometteurs pour les deux tâches. En raison des contraintes de ressources et de temps associées à ’lacquisition des mesures sur des échantillons réels, des spectres XRF synthétiques ont été utilisés. Ces spectres ont été générés à ’laide de simulations Monte Carlo et ont servi de données ’dentraînement pour les modèles, qui ont ensuite été testés sur des spectres provenant ’déchantillons réels. Des résultats encourageants ont été obtenus, les modèles entraînés démontrant leur capacité de détecter la présence ’déléments avec une précision de 95%, accompagnée ’dune erreur absolue moyenne de 3,42 % poids. De plus, une précision de classification équilibrée de 78.3% a été obtenue pour 22 classes de minéraux. Ces résultats soulignent le potentiel des modèles ’dapprentissage automatique pour prédire des informations caractéristiques telles que les classes minérales et les abondances des éléments chimiques, même ’lorsquils sont entraînés uniquement sur des données synthétiques. En combinaison avec ’dautres méthodes spectroscopiques, ’lanalyse XRF est prometteuse pour améliorer les méthodes de classification existantes.

La vaste distribution des amphores de type Gauloise 4 dans le monde méditerranéen durant le Haut-Empire témoigne de l’intense activité du commerce vinaire de la Narbonnaise durant cette période. La diffusion de ce type d’amphore dans la Péninsule ibérique, attestée par quelques amphores, demeure encore mal connue. La récente découverte à Carthagène de plusieurs fragments de Gauloise 4 présentant de fortes ressemblances avec les productions de Narbonnaise nous a conduits à réaliser une série d’analyses chimiques afin de nous assurer de leur provenance. Ainsi, huit amphores ont été analysées par fluorescence de rayons-X et comparées à la base de données de la Maison de l’Orient de la Méditerranée, riche de plus de 700 résultats d’analyses d’amphores produites dans le sud de la France. Les données ont ensuite été traitées en utilisant une méthode statistique de partitionnement mixte combinant l’Analyse en composante principale et l’algorithme des Nuées dynamiques (dérivé de la méthode K-means). Les résultats ont ensuite été validés par une analyse factorielle discriminante associée à une validation croisée. Les probabilités d’attributions obtenues nous ont permis de conclure qu’au moins cinq des huit échantillons ont été fabriqués dans les ateliers de Narbonnaise., Ministerio de Ciencia e Innovación, Depto. de Prehistoria, Historia Antigua y Arqueología, Fac. de Geografía e Historia, TRUE, pub

Aims: To investigate the distribution and toxicity of ruthenium nanoparticles (Ru NPs) injected intravenously in mice. Methods: We synthesized Ru NPs, followed their biodistribution by x-ray fluorescence (XRF) imaging and evaluated organ toxicity by histopathology and gene expression. Results: Ru NPs accumulated, mainly in liver and spleen, where they were phagocyted by tissue macrophages, giving a transient inflammation and oxidative stress response that declined after 2 weeks. Ru NPs gradually accumulated in the skin, which was confirmed by microscopic examination of skin biopsies. Conclusion: Ru NP toxicity in recipient organs is transient. Particles are at least partially excreted by the skin, supporting a role for the skin as a nanoparticle clearing organ., QC 20231013

Two-photon polymerization (2PP) is an efficient technique to achieve high-resolution, three-dimensional (3D)-printed complex structures. However, it is restricted to photocurable monomer combinations, thus presenting constraints when aiming at attaining functionally active resist formulations and structures. In this context, metal nanoparticle (NP) integration as an additive can enable functionality and pave the way to more dedicated applications. Challenges lay on the maximum NP concentrations that can be incorporated into photocurable resist formulations due to the laser-triggered interactions, which primarily originate from laser scattering and absorption, as well as the limited dispersibility threshold. In this study, we propose an approach to address these two constraints by integrating metallic Rh NPs formed ex situ, purposely designed for this scope. The absence of surface plasmon resonance (SPR) within the visible and near-infrared spectra, coupled with the limited absorption value measured at the laser operating wavelength (780 nm), significantly limits the laser-induced interactions. Moreover, the dispersibility threshold is increased by engineering the NP surface to be compatible with the photocurable resin, permitting us to achieve concentrations of up to 2 wt %, which, to our knowledge, is significantly higher than the previously reported limit (or threshold) for embedded metal NPs. Another distinctive advantage of employing Rh NPs is their role as promising contrast agents for X-ray fluorescence (XRF) bioimaging. We demonstrated the presence of Rh NPs within the whole 2PP-printed structure and emphasized the potential use of NP-loaded 3D-printed nanostructures for medical devices., QC 20231114

With the development of X-ray free-electron lasers (XFELs), producing pulses of femtosecond durations comparable with the coherence times of X-ray fluorescence, it has become possible to observe intensity–intensity correlations due to the interference of emission from independent atoms. This has been used to compare durations of X-ray pulses and to measure the size of a focusedX-ray beam, for example. Here it is shown that it is also possible to observe the interference of fluorescence photons through the measurement of the speckle contrast of angle-resolved fluorescence patterns. Speckle contrast is often used as a measure of the degree of coherence of the incident beam or the fluctuations of the illuminated sample as determined from X-ray diffraction patterns formed by elastic scattering, rather than from fluorescence patterns as addressed here. Commonly used approaches to estimate speckle contrast were found to suffer when applied to XFEL-generated fluorescence patterns due to low photon counts and a significant variation of the excitation pulse energy from shot to shot. A new method to reliably estimate speckle contrast under such conditions, using a weighting scheme, is introduced. The method is demonstrated by comparing the speckle contrast of fluorescence observed with pulses of 3 fs to 15 fs duration.

Concrete is the most widely used man-made material in the world. Its versatility, strength, and relative ease of construction allow it to be used in the majority of civil infrastructure. However, concrete production plays a significant role in greenhouse gas emissions, accounting for around 8% of CO2 emissions worldwide. This thesis aims to reduce the demand for cement in concrete construction, thus reducing the carbon footprint of the concrete, by focusing on classifying and determining the effectiveness of seven different quarry by-products as partial replacements of cement. Several methods were utilized in this study to characterize the quarry by-products: particle size distribution, helium pycnometry, X-Ray diffraction, X-Ray fluorescence, scanning electron microscopy, and a modified ASTM C1897 Method A that utilizes isothermal calorimetry and thermogravimetric analysis. These various methods allowed for the determination of the physical properties (e.g., gradation, specific gravity, and morphology) and the chemical properties (e.g., mineralogy and reactivity in a cementitious system). The quarry by-products were classified as four granites, two limestones, and one greenstone. These quarry by-products were found to be non-pozzolanic and non-hydraulic. However, there are indications that there may be reactions with the various clays and feldspars in the quarry by-products with calcium hydroxide, which suggests a degree of reactivity that is not necessarily pozzolanic or hydraulic.

International Ocean Discovery Program (IODP) Expedition 385 focused on the impact of sill emplacement and fluid flow on subsurface biogeochemical processes in organic-rich sediments of the Guaymas Basin. It resulted in the drilling of eight sites with contrasted settings; Sites U1545 and U1546 were drilled in the northern basin and allowed the recovery of a deep sill at Site U1546; Sites U1547 and U1548 were drilled on an active hydrothermal vent called Ringvent; Sites U1549 and U1552 were drilled on the Sonora margin where cold seeps and hydrates were identified; Site U1550 was sampled as a replicate of Deep Sea Drilling Project (DSDP) Leg 64 Site 481 on an axial trough; and Site U1551 was drilled ~29 km southeast of the axial graben and was mainly terrigenous. The quantitative X-ray fluorescence data presented here were measured on squeeze cakes retrieved after squeezing of whole-round core segments for pore water extraction. Major elements (Al, Ca, Cl, Fe, K, Mg, Mn, Na, P, Si, Ti, and S) as well as minor/trace elements (As, Ba, Br, Ce, Co, Cr, Cu, La, Mo, Nb, Ni, Pb, Rb, Sc, Sr, V, Y, Zn, and Zr) are provided in this data report.

Zinc is an essential trace element with various functions in all living organisms. Its bioavailability is tightly controlled by a combination of nutritional availability, binding to proteins, location in cellular organelles, and the presence of zinc transporters. In humans, changes in zinc homeostasis, such as zinc deficiency, have varied impacts on individuals. Zinc affects growth, fertility, immune cell functioning, and disease progression. Zinc homeostasis is compromised in aging, whereby abnormal metabolism contributes to sub-clinical changes and cellular dysfunction that may underlie the early onset of (neuro-)degenerative diseases. Therefore, a better understanding of the normal function of this trace element in health and diseases is highly desired.

Plant-soil interactions affect arsenic and nutrient availability in arsenic-contaminated soils, with implications for arsenic uptake and tolerance in plants, and leaching from soil. In 22-week column experiments, we grew the arsenic hyperaccumulating fern Pteris vittata in a coarse- and a medium-textured soil to determine the effects of phosphorus fertilization and mycorrhizal fungi inoculation on P. vittata arsenic uptake and arsenic leaching. We investigated soil arsenic speciation using synchrotron-based spectromicroscopy. Greater soil arsenic availability and lower nutrient content in the coarse-textured soil were associated with greater fern arsenic uptake, lower biomass (apparently a metabolic cost of tolerance), and arsenic leaching from soil, due to lower transpiration. P. vittata hyperaccumulated arsenic from coarse- but not medium-textured soil. Mass of plant-accumulated arsenic was 1.2 to 2.4 times greater, but aboveground biomass was 74% smaller, in ferns growing in coarse-textured soil. In the presence of ferns, mean arsenic loss by leaching was 195% greater from coarse- compared to the medium-textured soil, and lower across both soils compared to the absence of ferns. In the medium-textured soil arsenic concentrations in leachate were higher in the presence of ferns. Fern arsenic uptake was always greater than loss by leaching. Most arsenic (>66%) accumulated in P. vittata appeared of rhizosphere origin. In the medium-textured soil with more clay and higher nutrient content, successful iron scavenging increased arsenic release from soil for leaching, but transpiration curtailed leaching.

The western Fram Strait is the only deep-water gateway connecting the Arctic Ocean and North Atlantic. Consequently, today, the western Fram Strait and the Northeast Greenland shelf receive cold, low saline Polar and Arctic Atlantic waters from the Arctic Ocean incorporated in the East Greenland Current, together with warmer, saline recirculated Atlantic Water masses derived from the West Spitsbergen Current. We present a multiproxy study (grain size distribution, XRF core scans, and benthic foraminiferal assemblages) based on the lower part of the radiocarbon dated marine sediment core DA17-NG-ST03-039G, covering the period from 13.3 to 3.9 cal ka BP. We reconstruct the deglacial conditions of the Northeast Greenland shelf together with Early to Mid Holocene fluctuations in subsurface Atlantic Water and Polar Water advection. The results show that the outer Northeast Greenland shelf was deglaciated and marine conditions were established prior to c. 13.3 cal ka BP. At this time, our data show Atlantic Water masses flowing beneath an extensive sea-ice cover in a glaciomarine setting, potentially related to the Bølling-Allerød warm period. Around 12.9 cal ka BP, the onset of high surface and bottom water productivity may be associated with the Younger Dryas onset. This was followed by a transition towards warmer bottom and subsurface water conditions from c. 11.7 until 10.2 cal ka BP caused by enhanced advection of Atlantic-derived water masses. A cold period with marginal ice zone conditions and enhanced East Greenland Current incursion is evident from 10.2 to 9.4 cal ka BP, succeeded by harsher sea-ice conditions and Atlantic Water inflow, prevailing until c. 7.5 cal ka BP. Holocene Thermal Maximum conditions, characterized by high surface and subsurface water productivity, were promoted by enhanced Atlantic Water flow to the shelf from c. 7.5 to 6.7 cal ka BP. In contrast, the transition towards a cold period with increased drift-ice transport via a strong East Gre

In a series of Polynesian pearls collected after short cultivation periods, early post-grafting mineral deposits were characterized by high resolution synchrotron-based X-ray fluorescence with unprecedented accuracy. Morphological patterns and elemental composition are correlated through simultaneous imaging processes. Evidence that aragonite and calcite occur in neighboring units during the earliest biomineralization stages reveals that the grafting process can result in a greater degradation than usually admitted in the widely shared ‘reversed shell’ concept. Compared with ultrastructure of the pristine nacreous tablets, this method enables a precise evaluation of the possible biological changes in the biomineralization mechanism during grafting.

The first results of portable in situ XRF analysis performed in rock art in the Argentinean Patagonia, with the aim of determine the pigments of the paintings, are presented in this work. Five archaeological sites with rock art in Las Chapas, Chubut, were studied. The paintings are characterized by red monochrome geometric and abstract motifs. As the paintings are very deteriorated or in very thin layers no other technique could be applied to study them before. The results are only indicative and they require additional techniques to determine mineral pigments, however in the well preserved red and yellow paintings, the color is attributed to the presence of minerals with Fe, like hematite or limonite respectively. Additionally, potentially primary sources of black and yellow pigments are given to know for the first time., En este trabajo se presentan por primera vez en Patagonia argentina, los estudios realizados in situ con un equipo portátil de fluorescencia de rayos X para identificar la composición pigmentaria de pinturas rupestres. Se estudiaron cinco sitios arqueológicos con manifestaciones rupestres de la localidad Las Chapas (Chubut) que se caracterizan por representar motivos geométricos y abstractos habitualmente monocromáticos. Las pinturas se presentan en ocasiones muy desvaídas y/o con un espesor muy delgado, motivo por el cual, no han podido ser implementados otros análisis a la fecha. Los resultados obtenidos son orientativos y requieren de técnicas complementarias, no obstante, en las pinturas rojas y amarillas bien conservadas se destaca la participación de minerales de Fe como materia pigmentaria que fueron interpretados como hematita e hidróxidos de hierro respectivamente. En la elaboración del color blanco se presume la utilización de yeso debido a la presencia de S y Ca en las lecturas. Complementariamente se dan a conocer potenciales fuentes primaria de materias primas pigmentarias de color negro y amarillo.

[EN] This paper focuses on the study of a group of metal artefacts recently recovered during the archaeological excavations in Vila do Touro (Central Portugal), i.e., 19 artefacts and a small metallic inclusion embedded in a pottery sherd. The objects have been analysed by an X-Ray Fluorescence spectrometer to characterise the elemental composition of metal artefacts. A Scanning Electron Microscope with X-ray Microanalysis System and an optical microscope were used to observe and chemically characterise the metal inclusion in the pottery. The fragment of an ingot was also analysed by a multicollector Inductively coupled plasma mass spectrometer to address issues bound to the provenance of raw material. The results revealed different compositional patterns (pure copper, binary bronze, i.e., Cu+Sn, leaded bronzes, i.e., Cu+Sn+Pb, and gold), while pointing out the Ossa Morena region (Southwest of the Iberian Peninsula) as likely source of copper used to produce the ingot., [ES] Este trabajo se centra en el estudio de un grupo de artefactos metálicos recuperados recientemente durante las excavaciones arqueológicas en Vila do Touro (Portugal Central), es decir, 19 artefactos y una pequeña inclusión metálica incrustada en las paredes de un fragmento de cerámica. Los objetos han sido analizados mediante un espectrómetro de fluorescencia de rayos X para caracterizar la composición elemental de los artefactos metálicos. Se utilizó un microscopio electrónico de barrido con sistema de microanálisis de rayos X y un microscopio óptico para observar y caracterizar químicamente la inclusión metálica en la cerámica. También se analizó el fragmento de un lingote mediante un espectrómetro de masas de plasma acoplado inductivamente multicolector para abordar cuestiones relacionadas con la procedencia de la materia prima. Los resultados revelaron diferentes patrones de composición (cobre puro, bronce binario, es decir, Cu+Sn, bronces con plomo, es decir, Cu+Sn+Pb, y oro), al tiempo que señalaron la región de Ossa Morena (suroeste de la Península Ibérica) como probable fuente del cobre utilizado para producir el lingote.

Presently, the development of analytical methods to determine elemental composition of vegetation samples is of significance in many different fields. This chapter discusses the details and potentials of different X-ray fluorescence (XRF) configurations in the field of multi-elemental analysis of vegetation samples. Most commonly used sample treatment procedures are also described. The chapter includes some of the many interesting applications of XRF in environmental and agronomic studies dealing with the analysis of vegetation samples. Some of the main advantages of XRF in the field of vegetation sample analysis over other atomic spectroscopic techniques include the simplicity of sample preparation and the possibility to determine elements such as P, S, Cl, and Br which can be of significance in biological processes.

Phosphorus (P) is essential for plant growth. Arbuscular mycorrhizal fungi (AMF) aid its uptake by acquiring P from sources distant from roots in return for carbon. Little is known about how AMF colonise soil pore-space, and models of AMF-enhanced P-uptake are poorly validated. We used synchrotron X-ray computed tomography to visualize mycorrhizas in soil and synchrotron X-ray fluorescence/X-ray absorption near edge structure (XRF/XANES) elemental mapping for P, sulphur (S) and aluminium (Al) in combination with modelling. We found that AMF inoculation had a suppressive effect on colonisation by other soil fungi and identified differences in structure and growth rate between hyphae of AMF and nonmycorrhizal fungi. Our results showed that AMF co-locate with areas of high P and low Al, and preferentially associate with organic-type P species over Al-rich inorganic P. We discovered that AMF avoid Al-rich areas as a source of P. Sulphur-rich regions were found to be correlated with higher hyphal density and an increased organic-associated P-pool, whilst oxidized S-species were found close to AMF hyphae. Increased S oxidation close to AMF suggested the observed changes were microbiome-related. Our experimentally-validated model led to an estimate of P-uptake by AMF hyphae that is an order of magnitude lower than rates previously estimated – a result with significant implications for the modelling of plant–soil–AMF interactions.

Tato studie se zaměřuje na získávání cínu a solidifikaci kalu ze zrcadlového broušení. K extrakci cínu z kalu se používají roztoky hydroxidů o různé koncentraci (0,1 – 10M). Kal je dále upravován technikou stabilizace a solidifikace s použitím běžného portlandského cementu jako pojiva. Vzorky byly hodnoceny pomocí rentgenové fluorescenční analýzy, vyluhovacích zkoušek a pevnosti v tlaku v případě solidifikovaných vzorků. Výsledky ukázaly, že v případě extrakce v 10M hydroxidu sodném bylo získáno téměř 57 % cínu jako sraženina. Optimální obsah pro solidifikaci kalu byl obsah 50 % cementu. Dále byl hodnocen vliv přídavku aktivního uhlí do solidifikačních směsí. Závěrem lze říct, že kal ze zrcadlového broušení se ukázal jako vhodný pro získávání cínu a solidifikovaný odpad lze považovat za odpad, který není nebezpečný., This study aims on tin recovery and solidification of mirror-grinding sludge. To extract tin from sludge, different hydroxide solutions (0.1 - 10M) are used. The sludge is also treated using the stabilization and solidification technique using ordinary Portland cement as a binder. Samples were evaluated using x-ray fluorescence analysis, leaching tests and compressive strength in the case of solidified samples. The results showed that nearly 57 % of tin was recovered as a precipitate in case of extraction in 10M sodium hydroxide. The 50 % of ordinary Portland cement was the optimal content for the solidification of sludge. The influence of active carbon addition into solidification mixtures was also evaluated. In conclusion, the mirror-grinding sludge was suitable for tin recovery, and its solidification resulted in non-hazardous waste. © 2022 Czech Environment Management Center. All rights reserved.

[ES] En la actualidad, existe una gran diversidad de aplicaciones industriales de los rayos X. En muchas de estas prácticas, no es infrecuente encontrarse con casos en los que el objeto que se pretende analizar presenta un recubrimiento metálico, ya sea como protección frente a la oxidación o con una función estética. Es en estos casos cuando se pone de manifiesto una de las debilidades de la utilización de rayos X: el reducido alcance que presentan en los medios densos como los metálicos. La presencia de estos recubrimientos metálicos puede distorsionar la medida que se pretende realizar cuando el blanco de interés es el sustrato, o directamente la imposibilitan. Sin embargo, esta problemática se torna más acuciante cuando la técnica requiere la detección de la fluorescencia generada por el haz, ya que la energía disponible de los fotones generados es incluso menor y pueden no ser capaces de atravesar el recubrimiento. El presente proyecto propone el estudio del alcance en profundidad que presenta un haz de rayos X en sistemas que presentan recubrimientos metálicos o, en general, una combinación de metales superpuestos, de forma que se puedan establecer límites de detección de la fluorescencia generada. Para ello, se realizarán modelos mediante códigos que emplean el Método de Monte Carlo para poder obtener una solución teórica y para contar una mayor capacidad de análisis. Los resultados obtenidos serán posteriormente validados mediante la realización de medidas de Fluorescencia de Rayos X sobre muestras con recubrimientos de espesor controlado obtenidas mediante electrodeposición. Los recubrimientos metálicos pueden generar alteraciones en los picos de fluorescencia de rayos X, de modo que oculten los picos asociados al sustrato. Estas alteraciones también pueden dificultar el conocimiento de la proporción en que el sustrato contiene el metal de recubrimiento. Los resultados que genere este proyecto podrán emplearse para el desarrollo posterior de correcciones qu, [EN] Nowadays, there is a great variety of industrial applications of X-rays. In many of this practices, it is not unusual to find cases in which the object to be irradiated may present a metallic covering or that the covering may contain this kind of materials, whether to be used as a protection against oxidation or to embellish the object it covers. In these cases, one of greatest weakness X-rays appears: its poor extent through dense media like metals. The presence of these metallic coatings can distort the measure to be carried out when the target of interest is the substrate, or directly make it impossible. However, this problem becomes more pressing when the technique requires detection of the fluorescence generated by the beam, since the available energy of the generated photons is even less, and they may not be able to pass through the coating. The present project proposes the study of the depth range presented by an X-ray beam in systems that have metallic coatings or, in general, a combination of overlapping metals, so that detection limits of the generated fluorescence can be established. To do this, models will be made using codes based on the Monte Carlo Method to obtain a theoretical solution and to have a greater capacity for analysis. Results obtained will be subsequently validated by performing X-ray fluorescence measurements on samples with controlled thickness coatings obtained by electrodeposition. Metal coatings can cause disturbances in X-ray fluorescence peaks, so as to hide the peaks associated with the substrate. These alterations can also make it difficult to know the proportion in which the substrate contains the coating metal. The results generated by this project can be used for the subsequent development of corrections that eliminate these effects in X-ray fluorescence measurements, so that the error associated with the results obtained by X-ray Fluorescence Analysis is reduced. This has a high importance in the different areas that use

X-ray fluorescence computed tomography (XFCT) is a molecular imaging technique that can be used to sense different elements or nanoparticle (NP) agents inside deep samples or tissues. However, XFCT has not been a popular molecular imaging tool because it has limited molecular sensitivity and spatial resolution. We present a benchtop XFCT imaging system in which a superfine pencil-beam X-ray source and a ring of X-ray spectrometers were simulated using GATE (Geant4 Application for Tomographic Emission) Monte Carlo software. An accelerated majorization minimization (MM) algorithm with an L1 regularization scheme was used to reconstruct the XFCT image of molybdenum (Mo) NP targets. Good target localization was achieved with a DICE coefficient of 88.737%. The reconstructed signal of the targets was found to be proportional to the target concentrations if detector number, detector placement, and angular projection number are optimized. The MM algorithm performance was compared with the maximum likelihood expectation maximization (ML-EM) and filtered back projection (FBP) algorithms. Our results indicate that the MM algorithm is superior to the ML-EM and FBP algorithms. We found that the MM algorithm was able to reconstruct XFCT targets as small as 0.25 mm in diameter. We also found that measurements with three angular projections and a 20-detector ring are enough to reconstruct the XFCT images.

The Historical and Cultural Heritage of Punta Begoña Galleries in Getxo (Bizkaia, North of Spain) are currently in restoration after being abandoned for years. For that reason, many graffiti, which directly affect the wall paintings, appear on most of their walls. Moreover, several graffiti overlap each other, which makes their removal more difficult. For all these reasons, the chemical characterization of these pigments is a priority to optimize the cleaning and consolidation treatments of wall paintings. That being the case, an analysis based on Raman spectroscopy and X-ray fluorescence was carried out to obtain information to help conservators remove the graffiti without damaging the mural paintings and the support. Nevertheless, the first step, using X-ray fluorescence and Raman spectroscopy, involved the need for a database to compare the results and identify the compounds. Thus, different commercial inks were elementally and molecularly characterized to complete the existing databases. After this, an analysis of the inks was carried out that noted the presence of several organic pigments, such as phthalocyanines. Inorganic pigments such as titanium oxide were identified as well. After the analysis, the selection of the best removal process could be carried out to provide the most effective treatment, avoiding the “trial-and-error” classical practice.

The development by CSIRO of an indicator-mineral exploration technique for nickel in high-sulphur magmatic orebodies in Australia is described. Testing of potential indicator minerals such as cores of dunite, olivine using laser ablation, X-ray fluorescence and laser inductive breakdown spectroscopy to analyse the chemical signatures is discussed. Laboratory research studies on signals emitted by potential nickel sulphides in magmatic structures have been performed over a 3-y period and the recruitment of corporate partners to assist with the field work, e.g. Serpentine Bay, Hannan’s Lake, Kalgoorlie, is under way., The development by CSIRO of an indicator-mineral exploration technique for nickel in high-sulphur magmatic orebodies in Australia is described. Testing of potential indicator minerals such as cores of dunite, olivine using laser ablation, X-ray fluorescence and laser inductive breakdown spectroscopy to analyse the chemical signatures is discussed. Laboratory research studies on signals emitted by potential nickel sulphides in magmatic structures have been performed over a 3-y period and the recruitment of corporate partners to assist with the field work, e.g. Serpentine Bay, Hannan’s Lake, Kalgoorlie, is under way.

An investigation is presented of the preparation of calcium sulphate hemihydrate whiskers using either pure gypsum (CaSO4.2H2O) or complex jarosite waste (gypsum and ammonium jarosite) from a zinc hydrometallurgical process as raw materials. The samples are analysed by X-ray diffraction, X-ray fluorescence, scanning electron microscopy and Raman spectroscopy. Under autoclaved hydrothermal conditions, the effects on calcium sulphate hemihydrate morphology of using pure gypsum alone or in combination with Fe3+ or (NH4)+ impurity ions are described. The results show that pure gypsum alone produces calcium sulphate hemihydrate crystals with a high aspect ratio (50); the diameter of the crystals increases and the aspect ratio of the calcium sulphate hemihydrate decreases with increasing addition of Fe3+ or (NH4)+ ions. Calcified jarosite sediment containing mostly gypsum and ferric hydroxide is prepared by reacting complex jarosite waste with calcium oxide and washing with water. Treatment of the calcified jarosite sediment at 140 degrees C for 6 h in pH 5 solution under hydrothermal conditions provides calcium sulphate hemihydrate whiskers with a high aspect ratio (10-60), large diameter (1-4 micrometres) and smooth surface., An investigation is presented of the preparation of calcium sulphate hemihydrate whiskers using either pure gypsum (CaSO4.2H2O) or complex jarosite waste (gypsum and ammonium jarosite) from a zinc hydrometallurgical process as raw materials. The samples are analysed by X-ray diffraction, X-ray fluorescence, scanning electron microscopy and Raman spectroscopy. Under autoclaved hydrothermal conditions, the effects on calcium sulphate hemihydrate morphology of using pure gypsum alone or in combination with Fe3+ or (NH4)+ impurity ions are described. The results show that pure gypsum alone produces calcium sulphate hemihydrate crystals with a high aspect ratio (50); the diameter of the crystals increases and the aspect ratio of the calcium sulphate hemihydrate decreases with increasing addition of Fe3+ or (NH4)+ ions. Calcified jarosite sediment containing mostly gypsum and ferric hydroxide is prepared by reacting complex jarosite waste with calcium oxide and washing with water. Treatment of the calcified jarosite sediment at 140 degrees C for 6 h in pH 5 solution under hydrothermal conditions provides calcium sulphate hemihydrate whiskers with a high aspect ratio (10-60), large diameter (1-4 micrometres) and smooth surface.

This work presents the results of studies on obtaining ferromanganese concentrate from technogenic manganese containing raw materials with grain size less than 10 mm. It is found that the main valuable minerals of the feedstock are psilomelane, pyrolusite, bementite; the rock-forming minerals consist of quartz and kaolinite, often saturated with finely dispersed iron compounds. Sieving and concentration of raw materials of - 10 + 5 mm and - 2 + 0.2 mm in a two-chamber jigging machine with separation of two concentrates and tailings produced a joint manganese concentrate with 35.1% manganese content and 11.5% iron content with 78.23% manganese recovery. The obtained manganese concentrate is suitable for further metallurgical processing., This work presents the results of studies on obtaining ferromanganese concentrate from technogenic manganese containing raw materials with grain size less than 10 mm. It is found that the main valuable minerals of the feedstock are psilomelane, pyrolusite, bementite; the rock-forming minerals consist of quartz and kaolinite, often saturated with finely dispersed iron compounds. Sieving and concentration of raw materials of - 10 + 5 mm and - 2 + 0.2 mm in a two-chamber jigging machine with separation of two concentrates and tailings produced a joint manganese concentrate with 35.1% manganese content and 11.5% iron content with 78.23% manganese recovery. The obtained manganese concentrate is suitable for further metallurgical processing.

Phosphorus slag, the basis of which is wollastonite, is a waste product of the phosphorus industry. The study of phosphorus slag as a uranium sorbent is of theoretical and practical interest. In the course of the research, comparable data were obtained on the sorption of the initial and activated slag by different reagents. The optimal conditions for the activation of phosphorus slag in order to increase its sorption properties have been determined. When the slag is activated with a sodium chloride solution, the content of iron, magnesium, calcium, aluminium and silicon decreases. Such defects contribute to an increase in the degree of sorption of uranium by phosphorus slag., Phosphorus slag, the basis of which is wollastonite, is a waste product of the phosphorus industry. The study of phosphorus slag as a uranium sorbent is of theoretical and practical interest. In the course of the research, comparable data were obtained on the sorption of the initial and activated slag by different reagents. The optimal conditions for the activation of phosphorus slag in order to increase its sorption properties have been determined. When the slag is activated with a sodium chloride solution, the content of iron, magnesium, calcium, aluminium and silicon decreases. Such defects contribute to an increase in the degree of sorption of uranium by phosphorus slag.

Two groups, each of six bronze tools thought to be part of a single hoard from the Palaepaphos area but without any archaeological context, have been studied and their composition determined by portable X-ray fluorescence (pXRF). In addition to a shovel, a double adze, two double axes and a socketed chisel, seven of the tools are of a type known as ploughshares which previous studies have dated to the 12th century BC and have identified as made in Cyprus but also exported to ther Aegean. Unlike traditional iron ploughshares with their long sockets and short points, these are long blades with convex ends and sockets too short to have been fixed to the wooden part of a plough, suggesting they were designed as mattocks or, it is proposed, as mining tools suitable for the friable Cypriot copper sulphide deposits, although no such tools have yet been found in a mine. In the absence of accompanying scrap metal, ingot fragments or moulds to identify the set as a founder's hoard, chemical analysis does provide some evidence of a similar relatively pure Cu metal, with low Pb and Fe, traces of NI and no detectable As, S or Zn, in the majority of the artefacts; a slightly higher Pb concentration in two indicates the possibility of recycled metal having been used in their manufacture. Three tools carry small sunken cross-shaped marks that could perhaps be a workshop mark., Two groups, each of six bronze tools thought to be part of a single hoard from the Palaepaphos area but without any archaeological context, have been studied and their composition determined by portable X-ray fluorescence (pXRF). In addition to a shovel, a double adze, two double axes and a socketed chisel, seven of the tools are of a type known as ploughshares which previous studies have dated to the 12th century BC and have identified as made in Cyprus but also exported to ther Aegean. Unlike traditional iron ploughshares with their long sockets and short points, these are long blades with convex ends and sockets too short to have been fixed to the wooden part of a plough, suggesting they were designed as mattocks or, it is proposed, as mining tools suitable for the friable Cypriot copper sulphide deposits, although no such tools have yet been found in a mine. In the absence of accompanying scrap metal, ingot fragments or moulds to identify the set as a founder's hoard, chemical analysis does provide some evidence of a similar relatively pure Cu metal, with low Pb and Fe, traces of NI and no detectable As, S or Zn, in the majority of the artefacts; a slightly higher Pb concentration in two indicates the possibility of recycled metal having been used in their manufacture. Three tools carry small sunken cross-shaped marks that could perhaps be a workshop mark.

Mineral distributions can be determined in drill core samples from a Carlin-type gold deposit using micro-X-ray fluorescence raster data and long-wave infrared (LWIR) spectra can be interpreted using a Random Forest machine-learning approach to predict mineral species and abundances. Bruker AMICS software was used to identify mineral species from micro-XRF raster data, which revealed that many individual sample spots were mineral mixtures due to the fine-grained nature of the samples. To estimate the mineral abundances in each pixel, a linear programming (LP) approach was used on quantified micro-XRF data. Quantification of spectra was completed using a fundamental parameters (FP) standardless approach. Results of the FP method compared with standardised wavelength dispersive spectrometry (WDS)-XRF of the same samples showed that the FP method was precise (R2 values of 0.98–0.97) although giving a slight overestimate of Fe and K and an underestimate of Mg abundance. This approach is transferable to any ore deposit, but particularly useful in sedimentary-hosted ore deposits where ore and gangue minerals are often fine-grained and difficult to distinguish in hand specimen. In the second part of the study, hydrothermally altered carbonate rock core samples from the Fourmile Carlin-type Au discovery, Nevada, were analysed by LWIR and LP-derived mineral abundances from quantified micro-XRF data were used as training data to construct a series of Random Forest regression models. The models produced mineral proportion estimates with root mean square errors of 1.17 to 6.75% (model predictions) and 1.06 to 6.19% (compared with quantitative X-ray diffraction data) for calcite, dolomite, kaolinite, white mica, phlogopite, K-feldspar, and quartz. Using the method presented, LWIR spectroscopy can be used to overcome the limitations inherent with the use of short-wave infrared (SWIR) in fine-grained, low reflectance rocks. This new approach can be applied to any deposit type, imp, Mineral distributions can be determined in drill core samples from a Carlin-type gold deposit using micro-X-ray fluorescence raster data and long-wave infrared (LWIR) spectra can be interpreted using a Random Forest machine-learning approach to predict mineral species and abundances. Bruker AMICS software was used to identify mineral species from micro-XRF raster data, which revealed that many individual sample spots were mineral mixtures due to the fine-grained nature of the samples. To estimate the mineral abundances in each pixel, a linear programming (LP) approach was used on quantified micro-XRF data. Quantification of spectra was completed using a fundamental parameters (FP) standardless approach. Results of the FP method compared with standardised wavelength dispersive spectrometry (WDS)-XRF of the same samples showed that the FP method was precise (R2 values of 0.98–0.97) although giving a slight overestimate of Fe and K and an underestimate of Mg abundance. This approach is transferable to any ore deposit, but particularly useful in sedimentary-hosted ore deposits where ore and gangue minerals are often fine-grained and difficult to distinguish in hand specimen. In the second part of the study, hydrothermally altered carbonate rock core samples from the Fourmile Carlin-type Au discovery, Nevada, were analysed by LWIR and LP-derived mineral abundances from quantified micro-XRF data were used as training data to construct a series of Random Forest regression models. The models produced mineral proportion estimates with root mean square errors of 1.17 to 6.75% (model predictions) and 1.06 to 6.19% (compared with quantitative X-ray diffraction data) for calcite, dolomite, kaolinite, white mica, phlogopite, K-feldspar, and quartz. Using the method presented, LWIR spectroscopy can be used to overcome the limitations inherent with the use of short-wave infrared (SWIR) in fine-grained, low reflectance rocks. This new approach can be applied to any deposit type, imp

The Chatham Island Duck, Anas chathamica, is one of many New Zealand bird species that became extinct after Polynesian arrival. The Chatham Island Duck was a large flightless bird, with salt glands on its skull, which led to the hypothesis that it lived in a marine habitat. We tested this hypothesis using a combination of stable isotope analysis (carbon and nitrogen) and analysis of morphoanatomical features. We also conducted a comparative analysis with other anatids from the Chatham Islands and New Zealand. Furthermore, we trialled the non-destructive technique of portable X-ray fluorescence (elemental composition of bones) to assess whether it can be helpful for reconstructing the ecology and habitat of extinct species. We obtained data from museum specimens: 12 samples of A. chathamica and 55 of other anatids for isotope analysis; and 23 samples of A. chathamica and 63 of other anatids for X-ray fluorescence. Results from isotope analysis, supported by anatomical features, show that A. chathamica had a more fully marine diet than previously hypothesised, mainly composed of invertebrates. The large body size of A. chathamica is possibly related to territoriality and combat, which is also supported by the presence of carpal weaponry. Our data demonstrate the importance that the marine environment likely played in the life of this extinct species, while highlighting the key role natural history collections can have in ecological studies.

With permafrost thaw, significant amounts of organic carbon (OC) previously stored in frozen deposits are unlocked and become potentially available for microbial mineralization. This is particularly the case in ice-rich regions such as the Yedoma domain. Excess ground ice degradation exposes deep sediments and their OC stocks, but also mineral elements, to biogeochemical processes. Interactions of mineral elements and OC play a crucial role for OC stabilization and the fate of OC upon thaw, and thus regulate carbon dioxide and methane emissions. In addition, some mineral elements are limiting nutrients for plant growth or microbial metabolic activity. A large ongoing effort is to quantify OC stocks and their lability in permafrost regions, but the influence of mineral elements on the fate of OC or on biogeochemical nutrient cycles has received less attention and there is an overall lack of mineral element content analyses for permafrost sediments. Here, we combine portable X-ray fluorescence (pXRF) with a bootstrapping technique to provide i) the first large-scale Yedoma domain Mineral Concentrations Assessment (YMCA) dataset, and ii) estimates of mineral element stocks in never thawed (since deposition) ice-rich Yedoma permafrost and previously thawed and partly refrozen Alas deposits. The pXRF method for mineral element quantification is non-destructive and offers a complement to the classical dissolution and measurement by optical emission spectrometry (ICP-OES) in solution. Using this method, mineral element concentrations (Si, Al, Fe, Ca, K, Ti, Mn, Zn, Sr and Zr) were assessed on 1,292 sediment samples from the Yedoma domain with lower analytical effort and lower costs relative to the ICP-OES method. The pXRF measured concentrations were calibrated using alkaline fusion and ICP-OES measurements on a subset of 144 samples (R2 from 0.725 to 0.996). The results highlight that i) the mineral element stock in sediments of the Yedoma domain (1,387,000 km2) is higher

With permafrost thaw, significant amounts of organic carbon (OC) previously stored in frozen deposits are unlocked and become potentially available for microbial mineralization. This is particularly the case in ice-rich regions such as the Yedoma domain. Excess ground ice degradation exposes deep sediments and their OC stocks, but also mineral elements, to biogeochemical processes. Interactions of mineral elements and OC play a crucial role for OC stabilization and the fate of OC upon thaw, and thus regulate carbon dioxide and methane emissions. In addition, some mineral elements are limiting nutrients for plant growth or microbial metabolic activity. A large ongoing effort is to quantify OC stocks and their lability in permafrost regions, but the influence of mineral elements on the fate of OC or on biogeochemical nutrient cycles has received less attention and there is an overall lack of mineral element content analyses for permafrost sediments. Here, we combine portable X-ray fluorescence (pXRF) with a bootstrapping technique to provide i) the first large-scale Yedoma domain Mineral Concentrations Assessment (YMCA) dataset, and ii) estimates of mineral element stocks in never thawed (since deposition) ice-rich Yedoma permafrost and previously thawed and partly refrozen Alas deposits. The pXRF method for mineral element quantification is non-destructive and offers a complement to the classical dissolution and measurement by optical emission spectrometry (ICP-OES) in solution. Using this method, mineral element concentrations (Si, Al, Fe, Ca, K, Ti, Mn, Zn, Sr and Zr) were assessed on 1,292 sediment samples from the Yedoma domain with lower analytical effort and lower costs relative to the ICP-OES method. The pXRF measured concentrations were calibrated using alkaline fusion and ICP-OES measurements on a subset of 144 samples (R2 from 0.725 to 0.996). The results highlight that i) the mineral element stock in sediments of the Yedoma domain (1,387,000 km2) is higher

Many energy storage and energy conversion systems are based on the complexity of material architecture, chemistry, and interfacial interactions. To understand and thus ultimately control the energy applications calls for in situ/operando characterization tools. Over the years, in situ/operando soft x-ray spectroscopy has been developed for the studies of gas molecules, molecular liquids, catalytic, and electrochemical reactions. Soft x-ray spectroscopy offers electronic structure characterization of materials in energy conversion, energy storage, and catalysis regarding functionality, complexity of material architecture, and chemical interactions. It has been shown how to use the powerful in situ/operando soft x-ray spectroscopy characterization techniques of interfacial phenomena and how to reveal the mechanism of charge transfer and chemical transformation of solid/gas and solid/liquid interfaces of energy storage and catalytic materials in a realistic environment. It has been demonstrated how to overcome the challenge that soft x-rays cannot easily peek into the high-pressure catalytic or liquid electrochemical reactions. The unique design of in situ/operando soft x-ray spectroscopy instrumentation and fabrication principle and examples of experiments are presented. Graphic Abstract: [Figure not available: see fulltext.]

We analyse changes in terrigenous sedimentation along the northwestern Australian margin to monitor the latitudinal migration of the Intertropical Convergence Zone (ITCZ) and the shifting boundaries of climatic belts during the last four glacial cycles. We integrate high-resolution X-ray fluorescence (XRF) scanning elemental records from Core SO257–18548 and International Ocean Discovery Program Site U1482, situated southwest of the Scott Plateau at the southern edge of the present-day monsoonal belt, and from Core SO257–18571, located within the dust-cyclone belt offshore Northwest Cape south of the Exmouth Plateau. The chronology of these sediment successions is based on 14C dating over the last glacial termination and on correlation of the benthic oxygen isotope record to the LR04 stack (Lisiecki and Raymo, 200) and Antarctic ice core chronology. Our XRF derived records of riverine terrigenous run-off and aeolian dust input reveal rapid intensification of monsoonal precipitation and reduction of atmospheric dust during the Younger Dryas and early Holocene as well as during the terminal phase of other major deglaciations. Short-lived monsoonal maxima in the early Holocene (~10 ka), MIS 5e (~130 ka), MIS 7 (~200, ~220 and ~ 240 ka), and MIS 9 (~280, ~305 and ~ 330 ka) coincide with maxima in atmospheric carbon dioxide and methane concentrations. Monsoon intensification occurs during maxima in Southern Hemisphere spring (September) insolation, when intense heat low pressure cells over the Pilbara region trigger the southward shift of the ITCZ. Within the dust-cyclone belt, riverine sediment discharge was restricted to intervals of high atmospheric CO2 concentrations, when sea surface temperature thresholds promoted cyclone formation in the tropical Indian Ocean. Northwestern Australia remained dry and arid during MIS 5a-d, when the ITCZ was locked in a more northerly position and temperature thresholds were not attained.

Nanoparticle (NP)-based contrast agents enabling different imaging modalities are sought for non-invasive bio-diagnostics. A hybrid material, combining optical and X-ray fluorescence is presented as a bioimaging contrast agent. Core NPs based on metallic rhodium (Rh) have been demonstrated to be potential X-ray Fluorescence Computed Tomography (XFCT) contrast agents. Microwave-assisted hydrothermal method is used for NP synthesis, yielding large-scale NPs within a significantly short reaction time. Rh NP synthesis is performed by using a custom designed sugar ligand (LODAN), constituting a strong reducing agent in aqueous solution, which yields NPs with primary amines as surface functional groups. The amino groups on Rh NPs are used to directly conjugate excitation-independent nitrogen-doped carbon quantum dots (CQDs), which are synthesized through citrate pyrolysis in ammonia solution. CQDs provided the Rh NPs with optical fluorescence properties and improved their biocompatibility, as demonstrated in vitro by Real-Time Cell Analysis (RTCA) on a macrophage cell line (RAW 264.7). The multimodal characteristics of the hybrid NPs are confirmed with confocal microscopy, and X-ray Fluorescence (XRF) phantom experiments., QC 20211018

Nanoparticle (NP) based contrast agents detectable via different imaging modalities (multimodal properties) provide a promising strategy for noninvasive diagnostics. Core-shell NPs combining optical and X-ray fluorescence properties as bioimaging contrast agents are presented. NPs developed earlier for X-ray fluorescence computed tomography (XFCT), based on ceramic molybdenum oxide (MoO2) and metallic rhodium (Rh) and ruthenium (Ru), are coated with a silica (SiO2) shell, using ethanolamine as the catalyst. The SiO2 coating method introduced here is demonstrated to be applicable to both metallic and ceramic NPs. Furthermore, a fluorophore (Cy5.5 dye) was conjugated to the SiO2 layer, without altering the morphological and size characteristics of the hybrid NPs, rendering them with optical fluorescence properties. The improved biocompatibility of the SiO2 coated NPs without and with Cy5.5 is demonstrated in vitro by Real-Time Cell Analysis (RTCA) on a macrophage cell line (RAW 264.7). The multimodal characteristics of the core-shell NPs are confirmed with confocal microscopy, allowing the intracellular localization of these NPs in vitro to be tracked and studied. In situ XFCT successfully showed the possibility of in vivo multiplexed bioimaging for multitargeting studies with minimum radiation dose. Combined optical and X-ray fluorescence properties empower these NPs as effective macroscopic and microscopic imaging tools., QC 20210507

This article examines, from an interdisciplinary point of view and based on an analysis carried out with portable X-ray fluorescence equipment, a golden and enamelled altar set of the Cathedral of Huesca from the beginning of the late modern period. The analyses carried out reveal homogeneity in its chemical composition: the set is mostly gold with smaller amounts of copper and silver; it also showed traces of mercury, with no significant variations between the different points analysed. However, the weight of the chalice (the main object) is similar to the weight of another gilded silver chalice similar in size. This comparison suggests that the studied chalice composition cannot be pure gold, thus the hypothesis proposed is that all these ecclesiastical artifacts have an anomalously thick gilded layer, probably of several tens of microns., El presente artículo estudia, desde el punto de vista interdisciplinar y a partir de un análisis realizado con un equipo portátil de fluorescencia de rayos X, un conjunto de altar dorado y esmaltado de la catedral de Huesca de comienzos de la Edad Contemporánea. Los análisis revelan que existe homogeneidad en su composición química: el conjunto presenta mayoritariamente oro junto a cantidades menores de cobre y plata e incluye además trazas de mercurio sin variaciones significativas entre los distintos puntos analizados. Sin embargo, el peso del cáliz, como objeto principal, es similar al de otro de plata dorada de dimensiones parecidas, lo que resulta incompatible con una composición de oro puro, por lo que se propone la hipótesis de que todas las jocalias tengan un dorado de extraordinario grosor, probablemente de varias decenas de micras.

Intact rock properties are important for mining and geotechnical engineering because they are important design parameters for tunnels, rock foundations, rock slopes, among others. Some of the properties are also used as input parameters in some rock mass classification systems. Therefore, as rock properties are site-specific, there is need to investigate rock properties at a site especially when such site is used for engineering purpose. This paper documents the petrographic and X-ray fluorescence analyses, and physical and mechanical tests conducted to estimate the physical and mechanical properties of the two rock types (i.e. gabbro and granite) selected from quarries at Otanmäki, Finland. Mineral composition, grain size and chemical composition, water content, porosity, Brazilian tensile strength, uniaxial compressive strength, Young’s modulus, and Poisson ratio of the rock types were determined. Both gabbro and granite samples have fine to medium grained texture. The results of laboratory experiments conducted show that rock properties investigated have low to high variability. Simple and multiple regression analyses were performed and useful predictive models for estimating Brazilian tensile strength from physical test results were developed and validated.

The following article discusses the application of non-invasive and non-destructive analytical techniques to study the materials used in a mural painting from the former convent of Santo Domingo Tehuantepec, in Oaxaca, Mexico. The study is part of the restoration project for this heritage site and its ornamental finishes impacted by the earthquake of September 7th, 2017. The study characterizes the pictorial palette of the mural using XRF and digital microscopy and colorimetry to record the colors of the mural painting. The results indicated that very costly pigments with a high level of quality and durability (cinnabar or vermilion, orpiment, and bone black) had been used, which speaks to the historic and material importance of the decorations in the building., Este estudio muestra mediante técnicas analíticas no invasivas y no destructivas, los materiales de una pintura mural perteneciente al exconvento de Santo Domingo Tehuantepec, Oaxaca, México, construido entre 1544 y 1545, por los frailes dominicos. Este estudio es parte del proyecto de restauración del inmueble y sus acabados decorativos, afectados por el sismo del 7 de septiembre de 2017, se enfocó en la caracterización de la paleta pictórica mediante FRX y microscopia óptica digital, y por medio de colorimetría se registró el color de la pintura mural. Los resultados revelan el uso de pigmentos de costo, calidad y durabilidad muy altos: cinabrio o bermellón, oropimente y negro de hueso, esto demuestra la importancia histórica material de las decoraciones del recinto.

Calcareous nannofossil biostratigraphy and carbon-isotope stratigraphy on bulk organics of the middle-upper Eocene Souar Formation (Tunisia) allow for a refined stratigraphy of this interval in the southwestern Neo-Tethys margin. The Souar Formation represents the deepest sedimentary deposits of the central northern Tunisian Basin and was only dated previously by coarse data on planktonic foraminifera. Together with our new data, a correlation is proposed to previous Tunisian records of the Halk El Menzal carbonate platform to the NE and shallow-water deposits of central Tunisia to the SW, which leads us to the erection of a synthetic stratigraphic chart of the middle-upper Eocene in central and northeastern Tunisia. Our results allow for a review of the accurate position of the Lutetian / Bartonian and the Bartonian / Priabonian stage boundaries in Tunisia relative to calcareous nannofossil biohorizons. We apply Bayesian statistics to build our age-depth model which points to a hiatus in the Lutetian (CNE12 Zone) that we relate to the middle Lutetian regressive sequence leading to the Lu-4 M-cycle. Radiolarian-rich sediments and cherts of the late Lutetian and early Bartonian are interpreted as a response to an increase in productivity, tied to the seasonal upwelling of nutrient-rich waters. Correlation to other sections in Tunisia highlights the strong contrast in facies between the carbonate-rich sequences of the edges of the dorsal and the silica-rich deposition in the Souar Formation. This contrast is particularly pronounced in the interval before and across the Middle Eocene Climatic Optimum (MECO) characterized by a maximum of nummulitic carbonate production on the platform and a minimum of carbonate production in the deep basinal parts of the Tunisian dorsal, rather dominated by silica-rich sediments.

The archaeological study of ingots has gained in importance in recent years due to their links with metallurgical production, pre-monetary exchange and the emergence of weighing systems. However, in the northwestern Iberian Peninsula, which has one of the most outstanding protohistoric precious metalworking traditions in Western Europe, little attention has been paid to this method of accumulating raw material. This article provides the first systematic approach to the chemical composition of the precious metal ingots from this geographical area, based on the elemental analyses of 40 examples datable to the Late Iron Age and the early Roman presence. Two types of ingot composition have been identified: gold-silver-copper alloy and silver. In general, the former do not coincide with those documented in the jewellery from the hillforts (c. fourth–first centuries BC). This means that they could belong to the latest period of this metalworking tradition (c. first century BC–first century AD), when there was frequent use of cores of less valuable metals. In addition to their metallurgical function, silver ingots appear to have played an important role in the proto-monetary economy that characterised the early Roman presence. We propose that the different geographical distribution of these types of ingot was related to the diverse interactional dynamics generated between the local communities and the Romans during the long process of their conquest of this territory (138–19 BC).

To ensure that a structure will last throughout its service life, repairing reinforced concrete entails, among others, correctly marking off the area affected by aggressive agents that may deteriorate both the concrete and the steel. Chloride, the most damaging source of reinforcement corrosion, may diffuse to a greater or lesser distance from the surface depending on the ease of penetration. In this study, we calibrated a handheld X-ray fluorescence analyser (hXRF) and used it to quantify the chloride concentration in cement-based materials. The findings were verified against a series of samples of known concentration to establish a suitable correction factor. Chloride ions were quantified precisely and accurately with the hXRF instrument, and we calculated a correction factor of 1.16. The instrument and the information recorded were used to quantify the chloride ion content in different parts of an existing structure. The analyser identified apparently healthy areas that could, nonetheless, pose oxidation problems in the near future due to significant chloride concentration. Chloride quantification data at different depths can be used to draw diffusion or penetration profiles and to determine whether ion concentration around the reinforcement is within the recommended limits. The method developed can be applied in situ to quickly locate the most critical areas.

Over the last few years, the Federal Institute for material research (BAM, Berlin) together with the Centre for the Study of Manuscript Cultures (CSMC, University of Hamburg) have initiated a systematic material investigation of black inks produced from Late Antiquity to the Middle Ages (ca. fourth century CE–fourteenth/fifteenth centuries CE), aimed primarily at extending and complementing findings from previous sporadic studies. Part of this systematic investigation has focused on Egyptian Coptic manuscripts, and the present preliminary study is one of its outputs. It centres on a corpus of 45 Coptic manuscripts—43 papyri and 2 ostraca—preserved at the Palau-Ribes and Roca-Puig collections in Barcelona. The manuscripts come from the Monastery of Apa Apollo at Bawit, one of the largest monastic settlements in Egypt between the Late Antiquity and the Early Islamic Period (sixth–eighth centuries CE). The composition of their black inks was investigated in situ using near-infrared reflectography (NIRR) and X-ray fluorescence (XRF). The analyses determined that the manuscripts were written using different types of ink: pure carbon ink; carbon ink containing iron; mixed inks containing carbon, polyphenols and metallic elements; and iron-gall ink. The variety of inks used for the documentary texts seems to reflect the articulate administrative system of the monastery of Bawit. This study reveals that, in contrast to the documents, written mostly with carbon-based inks, literary biblical texts were written with iron-gall ink. The frequent reuse of papyrus paper for certain categories of documents may suggest that carbon-based inks were used for ephemeral manuscripts, since they were easy to erase by abrasion.

Este artículo muestra el estudio arqueométrico realizado sobre una escultura de Livia, hallada en la ciudad romana de Asido (actual Medina Sidonia, Cádiz, España), conservada en dos partes disociadas (cabeza y cuerpo), con objeto de ampliar el conocimiento sobre el hallazgo escultórico localizado actualmente en el museo de Cádiz. Estas piezas elaboradas en mármoles blancos han sido analizadas desde el punto de vista mineralógico-petrográfico y geoquímico y posteriormente, se ha llevado a cabo un estudio comparativo con material de canteras explotadas y comercializadas en el sur de Hispania, así como con otros mármoles foráneos de amplio uso en época romana en la provincia Baetica. Los resultados analíticos indican que ambas piezas, aunque con rasgos texturales y composicionales diferentes, pueden provenir de una misma cantera. Los rasgos petrográficos son coincidentes con otras variedades tanto locales como foráneas, pero sus componentes químicos mayoritarios y trazas han permitido establecer como origen más probable las canteras de Almadén de la Plata (Sevilla, España). El mármol de la cabeza de tamaño de grano grueso, aspecto translúcido y sacaroideo presenta contenido en Cl y Zn, Zr y La; que permiten atribuir como origen a una variedad de mármol blanco calcítico translucido con venas rosáceas, típico de Almadén de la Plata. Por otra parte los contenidos similares en MgO, Fe2O3, Ba y trazas de Th observados en el mármol del cuerpo, indican su correlación con una variedad de mármol blanco de tamaño de grano más heterogéneo con venas grisáceas y textura bandeada, donde se alternan bandas de grano medio a grueso con bandas de grano más fino, también típico de estas antiguas canteras. Este estudio también pone de manifiesto la cuidadosa selección del material que se usaba en la elaboración de las cabezas-retratos de las esculturas romanas, This paper shows the archaeometric study carried out on a sculpture of Livia, found in the city of Asido (Medina Sidonia, Cádiz, Spain), conserved in two dissociated parts (head and body), in order to expand the knowledge about the sculptural find, currently located in the museum of Cádiz. These pieces made of white marbles have been analyzed from the mineralogicalpetrographic and geochemical point of view and later, a comparative study has been carried out with material from quarries exploited and marketed in southern Hispania, as well as with other foreign marbles widely used in Roman times in the Baetica province. The analytical results indicate that both pieces, although with different textural and compositional features, may come from the same quarry. The petrographic features coincide with other local and foreign varieties, but their major and traces chemical components allowed to establish the quarries of Almadén de la Plata (Seville, Spain) as the most probable origin. The marble of the head of coarse grain size, translucent and saccharoid appearance presents content of Cl y Zn, Zr and La; that allow to attribute as origin to a variety of translucent calcitic white marble with pinkish veins typical from Almadén de la Plata. On the other hand, the similar contents in MgO, Fe2O3, Ba and traces of Th observed in the marble of the body, indicate its correlation with a variety of white marble of more heterogeneous grain size with grayish veins and banded texture, where bands of medium to coarse grain with finer grain bands, also typical of these old quarries. This study also shows the careful selection of the material that was used in the elaboration of the heads-portraits of the Roman sculptures., Este artigo mostra o estudo arqueométrico realizado sobre uma escultura de Lívia, encontrada na cidade romana de Asido (atual Medina Sidonia, Cádiz, Espanha), conservada em duas partes dissociadas (cabeça e corpo), a fim de ampliar o conhecimento sobre o achado escultórico atualmente localizado no museu de Cádiz, que contribui para a sua restituição completa e para melhorar a sua musealização. Essas peças elaboradas em mármores brancos foram analisadas do ponto de vista mineralógico-petrográfico e geoquímico e, posteriormente foi realizado um estudo comparativo com materiais de pedreiras exploradas e comercializadas no sul da Hispânia, bem como com outros mármores estrangeiros de amplo uso na época romana na província de Baetica. Os resultados analíticos indicam que ambas as peças, embora com características texturais e composicionais diferentes, podem ser provenientes da mesma pedreira. As características petrográficas coincidem com outras variedades locais e estrangeiras, mas os seus componentes químicos maioritários e vestigiais permitiram estabelecer as pedreiras de Almadén de la Plata (Sevilha, Espanha) como a origem mais provável. O mármore da cabeça, de granulometria grossa, aspeto translúcido e sacarídeo apresenta teores de Cl e Zn, Zr e La que permitem atribuir como origem uma variedade de mármore branco calcítico translúcido com veios rosados, típico de Almadén de la Plata. Por outro lado, os teores semelhantes de MgO, Fe2O3, Ba e vestígios de Th observados no mármore do corpo, indicam a sua correlação com uma variedade de mármore branco de granulometria mais heterogénea com veios acinzentados e textura em faixas, com faixas de grão médio a grosso alternam com bandas de grão mais fino, também típicas destas pedreiras antigas. Este estudo mostra também a seleção criteriosa do material que foi utilizado na elaboração dos cabeçasretratos das esculturas romanas.

A Master of Science thesis in Civil Engineering by Huda Aslam entitled, “Evaluation of Microplastics in Beach Sediments along the Coast of Dubai, U.A.E”, submitted in May 2019. Thesis advisor is Dr. Tarig Ali and thesis co-advisor is Dr. Md. Mortula. Soft and hard copy available., The unprecedented increase in consumption in conjunction with poor management of plastic waste have resulted in global contamination of both terrestrial and marine environments. Plastic debris undergoes fragmentation, resulting in the formation of microplastics, a synthetic polymers less than 5 mm in size. Significant amounts of microplastics have been globally observed in beach sediments. However, no studies have addressed microplastic contamination of marine sediments and/or coastal water in the United Arab Emirates. In this study, microplastic contamination in beach sediments of sixteen beaches along the Arabian Gulf coast in Dubai have been studied. Five samples of beach sediment were collected approximately from 1 cm below the surface from each beach along a 100 m stretch using a 0.5 m by 0.5 m, steel quadrant along the wrack lines. Density separation was used to extract microplastics from the sediment samples. The number of pieces of microplastics were identified under a 40X dissecting microscope and categorized by color and shape. Furthermore, microplastics polymer types were identified through FT-IR analysis. The results showed that the average weight of microplastic is 0.33 mg. g⁻¹ of sediment (or 953 mg.m⁻²) and the number of microplastic is 59.71 items.kg⁻¹ of sediment (or 165 items.m⁻²) in the study area. A total of 3366 pieces of microplastic were found in the 80 samples with 10 different colors; blue, red, green, yellow, black, white, grey, orange, pink, and transparent. The analysis showed that blue microplastics are more abundant in terms of numbers, while white ones are most abundant in terms of the number of microplastics per square meter (items.m⁻²) and number of microplastics per kg dry weight of sediment (items.kg⁻¹). Furthermore, four shapes of microplastics were identified including fiber (most dominant), string, pieces, and polystyrene spheres. FT-IR analysis was conducted to identify the polymer type of fibers and strings that were large eno, College of Engineering, Department of Civil Engineering

X-Ray fluorescence computed tomography (XFCT) is an emerging biomedical imaging technique, which demands the development of new contrast agents. Ruthenium (Ru) and rhodium (Rh) have spectrally attractive K ff edge energies, qualifying them as new XFCT bio-imaging probes. Metallic Ru and Rh nanoparticles are synthesized by polyol method, in the presence of a stabilizer. The effect of several reaction parameters, including reaction temperature time, precursor and stabilizer concentration, and stabilizer molecular weight, on the size of particles, were studied. Resultant materials were characterized in detail using XRD, TEM, FT-IR, DLS-zeta potential and TGA techniques. Ru particles in the size range of 1-3 nm, and Rh particles of 6-9 nm were obtained. At physiological pH, both material systems showed agglomeration into larger assemblies ranging from 12-104 nm for Ru and 25-50 nm for Rh. Cytotoxicity of the nanoparticles (NPs) was evaluated on macrophages and ovarian cancer cells, showing minimal toxicity in doses up to 50 mu g/mL. XFCT performance was evaluated on a small-animal-sized phantom model, demonstrating the possibility of quantitative evaluation of the measured dose with an expected linear response. This work provides a detailed route for the synthesis, size control and characterization of two materials systems as viable contrast agents for XFCT bio-imaging., QC 20200624

X-ray fluorescence tomography (XFCT) using nanoparticles (NPs) as contrast agents shows promise for high-spatial-resolution 3D molecular imaging. The technique has been demonstrated experimentally on phantoms as well as in small animals, i.e., mice. Parallel to experimental development, simulations play a key role in investigating the performance of existing and proposed XFCT arrangements. Up until recently, however, realistic simulations of small-animal XFCT have been unavailable due to the lack of appropriate, accurate and accelerated Monte Carlo (MC) based tools. We have developed the tools necessary to simulate highly realistic small-animal XFCT. Our MC tool, XRF-GPU is based on the accelerated open-source MC-GPU and allows simulations with speeds > 1000× faster than other existing MC codes capable of similar simulations. Using available high-resolution digital mouse phantoms, we can predict the performance of any XFCT imaging arrangement and produce the realistic data needed for future development of small-animal XFCT. Here we validate the simulations against our laboratory arrangement, capable of 200 µm spatial-resolution XFCT of mice. Comparisons using a phantom confirms that the simulations are accurate. Lastly, we compare simulated images with images acquired in vivo using our laboratory arrangement showing how simulations can be used to enhance the interpretation of experimental data., QC 20201130

Super duplex stainless steel consists of two phases: austenite and ferrite, and is a highly corrosion resistant material, with a wide range of applications. The corrosion resistance of stainless steels is determined by the performance of a spontaneously formed thin Cr oxide rich film with a thickness of 1-3 nm. This film makes the stainless steel passive towards further oxidation processes, corrosion. The passive film is a dynamic system where degradation and formation reactions occur simultaneously. Super duplex stainless steel is a multi-phase, multielement material which has a high corrosion resistance and the question is whether its microstructure and alloying elements are affecting its passive film properties. This thesis contains two parts: real time synchrotron measurements to study the degradation mechanism during anodic polarization which pushes the material toward oxidation processes; and ex-situ measurements to map the lateral thickness and microscopic elemental distribution in the passive film. The in-situ/operando synchrotron experiments combined several experimental techniques, including X-ray reflectivity (XRR), X-ray diffraction (XRD), X-ray fluorescence (XRF) and electrochemical impedance spectroscopy (EIS), to simultaneously characterize the structure and chemical/electrochemical properties, as well as their changes of the surface region of the samples. It was found that the oxide film became more defective with increasing potential, leading to a decreased density of the passive film. On the other hand, the Ni rich alloy surface layer below the oxide film showed an increasing density, indicating an increased concentration of heavy elements (Mo and Ni). The XRD data showed evidence of nanocrystalline passive film whereas the amorphousness of the passive film increased with increasing potential. The ex-situ investigations employed by hard X-ray photoelectron emission microscopy (HAXPEEM), providing chemical data from individual grains, En av de största anledningarna till att rostfria stål är så pass korrosions resistenta är på grund av en spontan oxidbildning på deras yta. Denna metalloxid består i huvudsak av Cr och Fr oxid och hydroxid men även utav Mo föreningar. Oxidskiktet är mycket tunt, mellan 1-3 nm tjockt och det bildas och ändras ständigt. Dess dynamiska karaktär i samband med att det är så tunt gör det svårt att definiera dess tjocklek, sammansättning och nedbrytningsprocess. Den passiva filmen består av två lager, ett oxidskikt och ett hydroxidskikt. På ett mycket rostbeständigt stål så som det höglegerade och tvåfasiga super duplex rostfritt stål, 2507, visas inga tecken på lokal nedbrytning under normala förhållanden. Dock så visar dess polarisationskurva att den går från passive till upplösningstillstånd. Hur nedbrytningen sker på en atomär nivå och hur det duplex stålets uppbyggnad samt sammansättning påverkar den passiva filmens nedbrytning eller avstående från nedbrytning är inte helt förstått. I denna avhandling har den passiva filmens nedbrytning följts utifrån flera aspekter så som den passiva filmens tjocklek, densitet och struktur samt genom att följa den kemiska avfällingen från ytan och därmed kunnat bättre beskriva nedbrytningsprocessen. Detta möjliggjordes genom att förskjuta potentialen eller den elektromotoriska kraften i riktning mot oxidering genom polarisation av materialet. Resultaten visade att med ökande potential blir den passiva filmen mer defekt vilket minskar dess barriäregenskaper och dess passivitet minskar. Under oxidskiktet finns ett skikt med högre densitet, vilket indikerar en berikning av Ni och Mo, med ungefär samma tjocklek. Denna undersökning visade att nedbrytningen av den passiva filmen är en process som sker under ett potentialförlopp. Den passiva har också beskrivits på lokal mikroskopisk nivå genom fotonelektron-emission-mikroskopi (HAXPEEM) analys, där kemiska spektra korreleras med mikroskopiska bilder och specifika områden kan väljas. De lok, QC 2020-08-17

Background: Exposure to metalworking fluids (MWFs) is a well-known cause of occupational contact dermatitis. Objectives: We aimed to (1) determine the amount of nickel, chromium, and cobalt in large samples of used and unused MWFs collected from metalworking plants in Denmark, and (2) evaluate a handheld x-ray fluorescence (XRF) device as a screening instrument for metals in MWFs. Methods: A handheld XRF device was used to screen for metals in MWFs. All samples were also analyzed for concentrations of nickel, chromium, and cobalt using graphite furnace atomic absorption spectroscopy (GFAAS). Results: GFAAS analysis showed that 13 of 80 samples (16.3%) contained >1 mg/kg (ppm) nickel (range: 6.4-17.7 mg/kg), 3 of 80 (3.8%) contained >1 (range: 1.4-3.1) mg/kg chromium, and 1 of 80 (1.3%) contained 1.3 mg/kg cobalt. XRF-screening detected nickel in eight samples (range: 2.5-15.5 mg/kg), but only one sample with 3.0 (±0.5) mg/kg was found subsequently to contain 9.9 (0.02) mg/kg nickel by GFAAS. Although no chromium was found by XRF analysis, cobalt was found in two samples with 6 (±1.5) mg/kg and 5 (±1.5) mg/kg, subsequently found to contain 0.1 (±0.01) mg/kg and 0.08 (±0.01) mg/kg by GFAAS. Similar concentrations of nickel were found in used (N = 6, range: 6.4-17.7 mg/kg) and unused MWFs (N = 7, range: 9.1-17.3 mg/kg). Conclusion: Considerable levels of nickel, chromium, and cobalt were found in some used and unused MWFs indicating that these might represent a source of metal allergy. The XRF device is a poor screening test for these metals in MWFs., QC 20200629