X-ray Fluorescence Research Articles

Geochemical suitability of Limestone for Cement making: A case study of Joldhal Formation

In this work, we investigate the industrial potentiality of limestone deposits in the Joldhal Formation of the Shimoga Schist Belt, Dharwar Craton. Based on their mineralogy, petrography, and geochemical characteristics. Twenty-five different limestone samples were collected from distinct locations and analyzed using X-ray fluorescence and X-ray diffraction techniques. Petrographically, these limestone deposits consist predominantly of calcite, quartz, chlorite, mica, micrites, etc. The X-ray diffraction studies indicated the dominance of calcite as an essential carbonate mineral, and quartz, kaolinite, chlorite, and mica/illite are major gangue minerals in the studied limestone. The results of the geochemical investigation of 25 samples indicated that the limestone from the study area exhibits a wide range of variation in LOI (27.99–42.82 wt%), SiO2 (0.21–19.60 wt%), CaO (27.80–55.50 wt%), Al2O3 (0.11–8.48 wt%), Fe2O3 (0.23–9.28 wt%), and MgO (0.51–9.79). Traces of K2O, Na2O, and TiO2 are found. This study illustrates how crucial it is to evaluate limestone's geochemical characteristics prior to cement making. Various factor analyses were calculated, like lime saturation factor, silica modulus, and alumina ratio, for suitable high-quality cement production. Bandigudda, Hanne, and Joldhal area valuable for cement manufacturing, unlike Medugondanahalli and Vitalapura, due to their impure quality and below-average parameter values. The results indicate suitability for cement production. The deposit's SiO2, Al2O3, and Fe2O3 content meet the ultimate moduli values of the raw material, indicating its suitability for cement production. This study emphasizes the significance of the geochemical evaluation of limestone for cement production

Matrizes cimentícias com o uso de resíduos de construção e demolição para redução do impacto ambiental de blocos de pavimentação

The construction industry is responsible for the intensive consumption of natural resources and the generation of large volumes of construction and demolition waste (CDW), which are often disposed of improperly. This research developed concrete blocks using recycled CDW aggregates, promoting sustainability and circular economy by reusing these materials in urban infrastructure. Waste was collected from a recycling plant over five months, selecting Brita 1, Brita 0, and Pó de Brita to compose the concrete mixes. Particle size distribution, bulk density, and specific gravity tests were performed, and blocks and specimens were molded with 100% replacement of natural aggregates by CDW. The compressive strength tests were carried out at 14 and 28 days, while the abrasion test was performed only at 28 days. X-ray fluorescence (XRF) and Scanning electron microscopy (SEM) were used to characterize the products. The results indicated a compressive strength of 34.3 MPa at 28 days, close to the minimum required by the standard (35 MPa). XRF analysis showed a predominance of SiO₂, CaO, Al₂O₃, Fe₂O₃, MgO, SO₃, and K₂O oxides, all within normative limits. Leaching and solubilization tests, conducted according to NBR 10005 and NBR 10006, classified the waste as non-hazardous and non-inert. This study demonstrates that using CDW in concrete block production is a viable and sustainable alternative, contributing to waste reduction, material reuse, and the development of sustainable urban infrastructure.

Valorization of marble sludge waste in biodiesel production using a central composite design.

This work addresses the scarcity of energy resources and environmental issues by concentrating on the synthesis of biodiesel by the transesterification of waste cooking oil with methanol. Marble sludge (MS), a novel heterogeneous catalyst, was used to speed up the rate of reaction. The catalyst's physical and chemical characteristics were thoroughly examined using a variety of methods, including X-ray diffraction, X-ray Fluorescence, SEM, particle size distribution, and BET analysis. Using the MS catalyst, the study investigated the impact of important parameters on the yield of biodiesel from waste cooking oil with the aid of response surface methodology using Design-Expert version 13 software. These parameters included temperature (50-70℃), reaction time (1-4h), catalyst concentration (1-5 wt%), and methanol-to-oil molar ratio (5-20mol/mol). Optimization of the parameters was performed for economic targets to lower the production cost of biodiesel. The results showed that a methanol-to-oil molar ratio of 20:1, a catalyst of 5 wt%, and a reaction time of 1h at 57℃ were the ideal parameters for obtaining a biodiesel yield of 93.5%. The resultant biodiesel revealed promising characteristics, such as a flash point of 160℃, a kinematic viscosity of 4 mm2/s, and a density of 0.871g/cm3. The study demonstrates the significant consequences and real-world advantages of using rational engineering methods to use MS as a very effective, stable, and easily recoverable catalyst for the long-term, sustainable generation of biodiesel from waste cooking oil.

X-ray fluorescence mapping of brain tissue reveals the profound extent of trace element dysregulation in stroke pathophysiology.

The brain is a privileged organ with regards to its trace element composition and maintains a robust barrier system to sequester this specialized environment from the rest of the body and the vascular system. Stroke is caused by loss of adequate blood flow to a region of the brain. Without adequate blood flow ischemic changes begin almost immediately, triggering an ischemic cascade, characterized by ion dysregulation, loss of function, oxidative damage, cellular degradation, and break down of the barrier that helps maintain this environment. Ion dysregulation is a hallmark of stroke pathophysiology and we observe that most elements in the brain are dysregulated after stroke. X-ray fluorescence-based detection of physiological changes in the neurometallome after stroke reveals profound ion dysregulation within the lesion and surrounding tissue. Not only are most elements significantly dysregulated after stroke, but the level of dysregulation cannot be predicted from a cell-level description of dysregulation. X-ray fluorescence imaging reveals that the stroke lesion retains<25% of essential K+ after stroke, but this element is not concomitantly elevated elsewhere in the organ. Moreover, elements like Na+, Ca2+, and Cl- are vastly elevated above levels available in normal brain tissue (>400%, >200%, and>150%, respectively). We hypothesize that weakening of the blood-brain-barrier after stroke allows elements to freely diffuse down their concentration gradient so that the stroke lesion is in equilibrium with blood (and the compartments containing brain interstitial fluid and cerebrospinal fluid). The changes observed for the neurometallome likely has consequences for the potential to rescue infarcted tissue, but also presents specific targets for treatment.

Visualization of Anion Vacancy Defect Annihilation in CZTSe Solar Cells by Hydrogen-Assisted Selenization with In Operando X-ray Nanoprobe Studies.

The traditional sulfur selenization process in Cu2ZnSn(S,Se)4 (CZTSSe) solar cell fabrication often results in the creation of localized anion vacancies (VS and VSe). These vacancies are considered harmful defects as they can trap carriers generated by light, leading to reduced solar cell efficiency. Moreover, concrete evidence has been lacking on the extent of the impact caused by these anion vacancies. Our research introduces a novel approach: the hydrogen-assisted selenization (HAS) process, specifically designed to minimize localized anion vacancies in Cu2ZnSnSe4 (CZTSe) solar cells. Our investigation, utilizing current-voltage (I-V) and admittance spectroscopy measurements, provides clear insights. We observed notable improvements in carrier collection efficiency and a discernible reduction in defect states. Furthermore, there was a significant decrease in the activation energy required within the solar cell device, dropping from 184 to 145 meV. To delve deeper into the structural and compositional aspects, we employed synchrotron-based X-ray nanoprobes. Through nanoscale X-ray fluorescence and hard X-ray beam-induced current measurements, we can directly observe and document the relationship between the local compositional distribution and photocurrent activity in operando. These comprehensive results furnish strong evidence that mitigating anion vacancies in the CZTSe layer can substantially improve the power conversion efficiency of the CZTSe solar cells. This advancement not only sheds light on the critical role of anion vacancies in solar cell performance but also underscores the effectiveness of the HAS process in enhancing overall device efficiency.

Substrate induced composition change during Ge2Sb2Te5 atomic layer deposition and study of initial reactions on SiO2 surface

Ge2Sb2Te5 (GST) is a well-known phase change material used in nonvolatile memory devices, photonics, and nonvolatile displays. This study investigates the impact of precursor sequence during atomic layer deposition (ALD) of GST from GeCl2.C4H8O2, SbCl3, and Te[(CH3)3Si]2 on Si/SiO2 substrates, focusing on growth per cycle, morphology, and composition along with initial precursor reactions on the substrate. We found that while thick layers approach stoichiometric Ge2Sb2Te5, a Ge-rich interfacial layer is initially formed, regardless of the binary ALD sequence used to start the deposition (GeTe vs Sb2Te3). Starting the ALD process with the GeTe-Sb2Te3 sequence results in a higher Ge content near the GST/SiO2 interface compared to the Sb2Te3-GeTe sequence. To understand these phenomena, we examine the initial precursor reactions on the SiO2 substrate by total reflection x-ray fluorescence spectrometry. The analysis reveals that SbCl3 exhibits lower reactivity with the SiO2 substrate than GeCl2.C4H8O2, and not all Ge adspecies react with the Te[(CH3)3Si]2 precursors. Additionally, the impact of the initial SiO2 surface on deposition extends over several ALD cycles, as the SiO2 surface only gradually gets covered by GST due to island growth. These processes contribute to the formation of a Ge-rich GST layer at the interface, irrespective of the precursor pulse sequence. These insights from the study may contribute to optimizing the initial deposition stages of GST and other ternary ALD processes to enable better composition control and enhanced device performance.

Characterization of the Elemental Composition of Aerosols Emitted in the Dry Season of the Pantanal Wetland, Brazil

The Brazilian Pantanal region experiences intense biomass burning during the dry season, releasing large quantities of gasses and particles into the atmosphere, which have serious implications on both the climate system and public health. Understanding the dynamics of these emissions is crucial for mitigating the impact on the ecosystem, its functioning, and potential anthropogenic disturbances. This study focused on analyzing emissions in the northern Pantanal during the 2022 drought. Concentrations of fine particulate matter (PM2.5), black carbon (BC), and 25 chemical elements were measured using gravimetry, reflectance analysis, and X-Ray fluorescence, respectively, from samples collected between August and October 2022. The average concentrations of PM2.5 and BC increased approximately 4-fold and 2.5-fold, respectively, compared to averages from a decade ago. Significant increases were also observed in elements such as sulfur (S), potassium (K), iron (Fe), and silicon (Si). The maximum concentrations were comparable to values typical of the southern Amazon, a region known for high deforestation rates and land use changes. Elemental analysis revealed substantial shifts in concentrations, primarily associated with biomass burning (BB) and soil suspension. Additionally, enrichment factor (Ef) analysis showed that lead (Pb) levels, correlated with human activities, were 200 times higher than those found under clean atmospheric conditions.

Adding More Shape to Nanoscale Reference Materials─LiYF4:Yb,Tm Bipyramids as Standards for Sizing Methods and Particle Number Concentration.

The increasing industrial use of nanomaterials calls for the reliable characterization of their physicochemical key properties like size, size distribution, shape, and surface chemistry, and test and reference materials (RMs) with sizes and shapes, closely matching real-world nonspheric nano-objects. An efficient strategy to minimize efforts in producing nanoscale RMs (nanoRMs) for establishing, validating, and standardizing methods for characterizing nanomaterials are multimethod nanoRMs. Ideal candidates are lanthanide-based, multicolor luminescent, and chemically inert nanoparticles (NPs) like upconversion nanoparticles (UCNPs), which can be prepared in different sizes, shapes, and chemical composition with various surface coatings. This makes UCNPs interesting candidates as standards not only for sizing methods, but also for element-analytical methods like laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS), quantitative bioimaging methods like X-ray fluorescence computed tomography (XFCT), and luminescence methods and correlative measurements. Here, we explore the potential of two monodisperse LiYF4:Yb,Tm bipyramids with peak-to-peak distances of (43 ± 2) nm and (29 ± 2) nm as size standards for small-angle X-ray scattering (SAXS) and tools for establishing and validating the sophisticated simulations required for the analysis of SAXS data derived from dispersions of nonspheric nano-objects. These SAXS studies are supplemented by two-dimensional (2D)-transmission electron microscopy measurements of the UCNP bipyramids. Additionally, the particle number concentration of cyclohexane dispersions of these UCNP bipyramids is determined by absolute SAXS measurements, complemented by gravimetry, thermogravimetric analysis (TGA), and inductively coupled plasma optical emission spectrometry (ICP-OES). This approach enables traceable particle number concentration measurements of ligand-capped nonspheric particles with unknown chemical composition.

Investigation of the Influence of Structure, Stoichiometry, and Synthesis Temperature on the Optical Properties of CdTe Nanoplatelets

Colloidal cadmium telluride (CdTe) nanoplatelets (NPLs) are promising materials for optoelectronic applications, such as photovoltaics and light-emitting diodes, due to their unique optical and electronic properties. However, controlling their growth, thickness, and stoichiometry remains challenging. This study explores the effect of synthesis temperature on the structural, optical, and stoichiometric properties of CdTe NPLs. CdTe NPLs were synthesized at temperatures of 170 °C, 180 °C, 190 °C, and 200 °C using colloidal methods. The resulting NPLs were characterized by UV–Vis absorption spectroscopy, photoluminescence (PL) spectroscopy, transmission electron microscopy (TEM), and total reflection X-ray fluorescence (TXRF) to assess their morphology, structure, and elemental composition. The results showed that the synthesis temperature significantly affected the NPL’s morphology and stoichiometry. Optimal stoichiometry was achieved at 180 °C and 190 °C, with the crystal structure transitioning from zinc blende at lower temperatures to wurtzite at higher temperatures. Optical properties, including luminescence intensity and emission peaks, also varied with temperature. The synthesis temperature is an important parameter in controlling the structural and optical properties of CdTe NPLs. The optimal conditions for obtaining NPLs with the best characteristics were identified at 190 °C, presenting important findings for further optimization of CdTe NPL synthesis for optoelectronic applications.

A Simple Neural Network for Estimating Fine Sediment Sources Using XRF and XRD

Suspended sediment (SS) has a wide range of negative effects such as increased water turbidity, altered habitat structures, sedimentation, and effects on hydraulic systems and environmental engineering projects. Nevertheless, the methods for accurately determining SS sources on a basin-scale are poorly understood. Herein, we used a simplified neural network analysis (NNA) model to identify the sources of SS in Japan’s Oromushi River Catchment Basin. Fine soil samples were collected from different locations of the catchment basin, processed, and separately analysed using X-ray fluorescence (XRF) and X-ray diffraction (XRD). The sampling stations were grouped according to the type of soil cover, vegetation type and land-use pattern. The geochemical components of each group were fed into the same neural network layer, and a series of equations were applied to estimate the sediment contribution from each group to the downstream side of the river. Samples from the same sampling locations were also analysed by XRD, and the obtained peak intensity values were used as the input in the NNA model. SS mainly originated from agricultural fields, with regions where the ground is covered with volcanic ash identified as the key sources through XRF and XRD analysis, respectively. Therefore, based on the nature of the surface soil cover and the land use pattern in the catchment basin, NNA was found to be a reliable data analytical technique. Moreover, XRD analysis does not incorporate carbon, and also provides detailed information on crystalline phases. The results obtained in this study, therefore, do not depend on seasonal uncertainty due to organic matter.

From STEM-EDXS data to phase separation and quantification using physics-guided NMF

Abstract We present the development of a new algorithm which combines state-of-the-art energy-dispersive X-ray (EDX) spectroscopy theory and a suitable machine learning formulation for the hyperspectral unmixing of scanning transmission electron microscope EDX spectrum images. The algorithm is based on non-negative matrix factorization (NMF) incorporating a physics-guided factorization model. It optimizes a Poisson likelihood, under additional simplex constraint together with user-chosen sparsity-inducing and smoothing regularizations, and is based on iterative multiplicative updates. The fluorescence of X-rays is fully modeled thanks to state-of-the-art theoretical work. It is shown that the output of the algorithm can be used for a direct chemical quantification. With this approach, it is straightforward to include a priori knowledge on the specimen such as the presence or absence of certain chemical elements in some of its phases. This work is implemented within two open-source Python packages, espm and emtables, which are used here for data simulation, data analysis and quantification. Using simulated data, we demonstrate that incorporating physical modeling in the decomposition helps retrieve meaningful components from spatially and spectrally mixed phases, even when the data are very noisy. For synthetic data with a higher signal, the regularizations yield a tenfold increase in the quality of the reconstructed abundance maps compared to standard NMF. Our approach is further validated on experimental data with a known ground truth, where state-of-the art results are achieved by using prior knowledge about the sample. Our model can be generalized to any other scanning spectroscopy techniques where underlying physical modeling can be linearized.

Coal structure evaluation and morphological properties that affect the coal usage in industries

AbstractThe contemporary research article is central to understanding coal structure evaluation and the morphological development impacting its utilization in different applications. Through Mineral Liberation Analysis (MLA) designs high content phyllosilicates minerals and swelling clay minerals were rationalized to provides a novel insight into enhanced coal beneficiation and the benefits of coal by-product re-utilization progressions that encourage safer environments and economic sustainability. This work commences with collection of five (5) different coal samples from the central district region in Botswana, sample characterization deploying Thermogravimetric coal analysis (TGA), x-ray fluorescence spectroscopy (XRF), x-ray diffraction (XRD), scanning electron microscopy (SEM) and the Hardgrove Grindability Index (HGI) test that was directed to quantification of the coal hardness and fracture toughness during milling. The cumulative objective was to understand the correlation that exists between the natural composition of the coal sample and their adaptation and application in various carbonaceous products. A solid connection was thus identified in the sulfur and phosphorus weight percentage inclusions in all the coal materials hence higher significance in sphalerite mineral phases (Zn, Fe) S critically increased the fracture toughness and hardness properties. Moreover, mineral amalgams intrinsic to the coal maceral such as aluminum oxides (Al2O3), silicate (SiO2), calcites (CaO), Iron oxide (Fe2O3), potassium feldspars (K − AlSi3O8), albite (Na − AlSi3O8), and anorthite (Ca − Al2Si2O8) compounds in alkali feldspars were detected in larger quantities. The coal industry has attracted much industrial attention to manufacturing foundations producing cement, ceramic tiles, paving bricks, and material synthesis and will continue to supply other economic sectors in the conceivable future. Graphical Abstract

Hydrological changes and its impacts on prehistoric human welfare in the western Tibetan Plateau since the last deglaciation

In recent decades, the rapidly changing climate environment in the Tibetan Plateau (TP) poses significant challenges to human survival and future sustainable development. The suitability and stability of the climate in the TP undoubtedly affected the living conditions and welfare of prehistoric humans. However, few studies have attempted to link climate stability and the survival of ancient humans, especially considering their lesser adaptability in responding to rapid environmental changes. The Xiada Co is a Neolithic period archaeological site in the western TP. In this study, we reconstructed the hydrological changes in the basin over the past 15,000 years using X-ray fluorescence (XRF) elemental analysis on the Xiada Co cores. The XRF results revealed three main paleoenvironmental units during the entire study interval. The late Pleistocene prior to ~10,000 cal year BP was characterized by more rapidly fluctuating hydrologic conditions. The early and middle Holocene (~10,000–4000 cal year BP) by stable hydrologic conditions, and the late Holocene to present by a return to more variable conditions. Using the calculation method of Square Chord Distance (SCD), a quantitative dissimilarity comparison was made regarding the climate variations in the western TP for 15 time periods. The results showed that the climate and hydrology were relatively stable during the period of occupation of the region (8500–7500 years BP), which provided a stable and suitable living environment for the hunter-gatherers at the site. This study illustrates how the paleoenvironment influenced the survival of hunter-gatherers in the extremely harsh western TP.

Simultaneous laser polishing and N-doping of niobium

Superconducting niobium is the base material for many modern particle accelerators. The high cleanliness requirements in all radio frequency superconductor technology have led to the development of complex cleaning processes in recent decades. High-pressure rinsing, heating processes under vacuum and gas atmospheres as well as chemical and electrochemical polishing are commonly applied procedures, that are required to obtain the properties needed for their application. In order to optimize the surface finish of Nb materials in a more environment-compatible way, i.e., with less energy consumption and avoiding hazardous liquids, we report on a combination of simultaneous N-doping and laser polishing here. A nanosecond laser was employed, and the prepared Nb surfaces were investigated with a combination of electron microscopy, x-ray fluorescence spectroscopy (EDX), optical profilometry, and x-ray absorption spectroscopy (EXAFS) to show the effect of different N2-pressures during the laser polishing procedure in an ultrahigh vacuum chamber. The results show that for N2-pressures above ca. 10−3 mbar, traces of nitrogen can be observed by both EDX and EXAFS. In parallel, a smoothing of the surfaces occur, with slightly different roughnesses and microstructures of the polycrystalline Nb surfaces depending on the N2-pressure.

Antibacterial Activity of Silver Nanoparticles Prepared from Camellia Sinensis Extracts in Multi-Drug Resistant Staphylococcus Aureus.

The nano-method has been used as a technique for creating novel, non-traditional antimicrobial agents. This effective method for treating infectious diseases has many advantages over conventional antibiotics, including increased efficacy against species that have developed drug resistance, and the ability to circumvent the development of resistance that disrupts a number of biological pathways. As a result, the objective of this study was to synthesize and characterize silver nanoparticles using phenolic compounds obtained from Camellia sinensis . The nanoparticles were then used as antibacterial agents on the multidrug resistant Staphylococcus aureus, as well as, biofilm formation mechanism were also investigated. Ten isolates of Staphylococcus aureus were acquired from the labs of the University of Baghdad's Genetic Engineering and Biotechnology Institute. The VITEK-2 system was used to confirm the diagnosis. Aqueous and methanolic extracts of Camellia sinensis leaves were used to create silver nanoparticles and obtain CAgNPs, which were then characterized using Atomic Fluorescence Microscopy (AFM), X-ray diffractometer (XRD), and Zeta potential analyzers. The extracts were put through a series of assays, including High-performance liquid chromatography (HPLC), antibacterial activity assessments, and the microtiter plate method to determine the lowest inhibitory concentration (MIC) and antibiofilm formation. Both aqueous and methanolic extracts containing silver nanoparticles included spherical nanoparticles that may be single or combined. The HPLC results showed the presence of two phenolic compounds (gallic acid and caffeine) by comparing their retention durations to those of the reference compounds. The results of the antibacterial activity of (CAgNPs) showed that the methanolic (CAgNPs) extract was more effective than the aqueous (CAgNPs) extract, producing inhibitory zones of 15.67 ± 0.58 and 20.33 ± 0.58 mm, at 375 and 750 ppm respectively, when compared to the aqueous (CAgNPs) extract, which produced inhibitory zones of 12.33 ± 0.58 and 15.67 ± 0.58 mm, respectively. The MIC result also showed that the CAgNPs methanolic extract was more effective than the CAgNPs aqueous extract. The MIC of the CAgNPs methanolic extract on S. aureus isolates were 11.718 and 23.43 µg/ml, while the MIC of the CAgNPs aqueous extract on all S. aureus isolates were 46.87 µg/ml except isolate No. 3 and 6 which was 11.718 and 93.75 µg/ml respectively. Additionally, The anti-biofilm in S. aureus was increased when CAgNPs methanolic extract were used compared with the CAgNPs aqueous extract, the CAgNPs methanolic extract inhibited 80%, 90% and 100% of the biofilm formation of S. aureus in 23.43, 46.87 and 93.75 µg/ml respectively, while the anti-biofilm activity of the CAgNPs aqueous extract on S. aureus isolates was 80% and 100% of the biofilm formation in 46.87 and 93.75 µg/ml respectively. The methanolic and aqueous leaves extracts from Camellia sinensis are a successful method for producing CAgNPs. The synthesized CAgNPs also have significant antibacterial activity against S. aureus, depending on the concentrations, and inhibit S. aureus biofilm formation.

Metal Contamination and Human Health Risk Assessment of Soils from Parks of Industrialized Town (Galati, Romania)

The aim of the present study was to evaluate the contamination state of the surface soil from 10 parks from Galati, Romania, and the health hazards of the soil. The soil samples, collected in each site from the playing ground and from the edge of the park, were analyzed by using combined Wavelength- (WDXRF) and Energy-Dispersive (EDXRF) X-ray fluorescence techniques. A total number of 27 chemical elements (Ag, Al, As, Ba, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sb, Sc, Sn, Sr, Ti, V, Zn and Zr) were quantified in the urban soils, and the results were compared to the normal and alert values from Romanian legislation for toxic trace elements, as well as with European and world average values of element concentrations. The mineralogical analyses were performed by Scanning Electron Microscopy with Energy-Dispersive X-ray Analysis (SEM-EDX) and the Attenuated Total Reflectance–Fourier Transform Infrared technique (ATR-FTIR). To assess the soil contamination and the impact on human health of the presence of potential toxic elements and heavy metals in the soil, a series of pollution and health risk indices were used. All the results indicated an unpolluted to moderately polluted soil. The soil samples collected from the edge of the parks presented higher values for the specific pollutants, which originated from heavy traffic, such as Cu, Cr, Zn and Pb. The non-carcinogenic and carcinogenic risk to children was assessed using estimated daily intake (EDI) in relation to the pathways whereby pollutants can enter the human body, such as ingestion, dermal contact, inhalation and vaporization. Using the obtained values for EDI, the hazard quotient and hazard index were determined, which strengthen the formerly issued presumption that soil pollution is moderate and, by itself, does not present any threat to children’s health.

FEATURES OF ELEMENTAL ANALYSIS OF DOLOMITES OF THE LOWER PERMIAN DEPOSITS BY X-RAY FLUORESCENCE SPECTROSCOPY

In this work, using the methods of scanning electron microscopy (SEM), X-ray phase analysis (XRF), X-ray fluorescence spectrometry (XFS) and thermogravimetric analysis (TGA), the physicochemical properties of dolomite rocks selected from one well at different depths of occurrence were studied. The SEM method shows that, depending on the depth of occurrence, dolomite is characterized by both ordinary crystals of rhombohedral morphology, the size of which varies from 50 to 80 microns along the diagonal axis, and unusual shapes, in the form of hexagonal plates up to 1 microns thick and 1 to 10 microns in diameter. It has been found that dolomite plates in places form spherical aggregates ranging in size from 20 to 40 microns. According to the RF analysis data, it was found that in samples of dolomite rock (of ordinary and unusual shape), after calcination at 1000 °C for 5 hours, there is a twofold increase in the molar stoichiometric ratio of Mg and Ca, compared with the initial (non-calcined) state of dolomite. By the XRD method, it was found that during calcination of dolomite samples, a phase transformation (CaMg(CO3)2 → CaO + MgO + 2CO2) is observed, in which lime (CaO) and periclase (MgO) phases are formed. Precision SEM studies have shown that periclase nanocrystals, whose size varies from 100 nm to 300 nm, are evenly distributed on the surface of larger lime fragments. As a result of numerous measurements of the X-ray spectra of the RF, it was found that the overlap of lime fragments with numerous periclase nanocrystals is the cause of a significant overestimation of the magnesium content after calcination of dolomite samples. It is concluded that in order to correctly conduct elemental analysis and obtain adequate information about the weight fraction of rock-forming oxides in dolomite samples, they must first be dissolved in hydrochloric acid. The method of sample preparation proposed by the authors for the correct elemental analysis of dolomite rocks has been tested on numerous samples, which showed convincing convergence of the data obtained by XRF (decomposition into rock-forming oxides) and XRF analysis.

Provenance and Paleo-Environment of the Late Carboniferous Bauxite Formations in Southern Shanxi

The Carboniferous Benxi Formation in southern Shanxi of North China has significant bauxite resource potential; however, the source of its metallogenic material and its sedimentary environment remain unclear. The microscopy, X-ray diffraction, X-ray fluorescence spectroscopy, and inductively coupled plasma mass spectrometry methods were applied in this study to examine the mineralogical, petrographic, and geochemical characteristics. Geochemical proxies of La/Y, Sr/Ba, Al2O3/TiO2, Zr/Sc, Th/Sc, La/Sc, and Th/Co were analyzed to investigate the paleo-depositional environment and provenance of the aluminum-bearing strata. The findings indicate that diaspores are the primary ore minerals in bauxite, while kaolinite and rutile are the predominant gangue minerals. Both the bauxite and claystone/aluminous rocks exhibit high enrichment in Li, Bi, and U, with relative enrichment in In, Sb, Th, Nb, and Ta. Li is notably concentrated in the claystone/aluminous rocks, reaching up to 1994.00 μg/g, primarily occurring in cookeite and boehmite, while U is highly concentrated in the bauxite. The aluminum-bearing strata were primarily formed under alkaline-reducing conditions, with changes in acidity and alkalinity of the environment during the sedimentary diagenetic process. Marine transgressions significantly impacted the sedimentary environment of the aluminum-bearing strata, and the paleoclimate was characterized as hot and humid. The principal factors contributing to enrichment of aluminum in the sedimentary basin were the in situ weathering of aluminum-rich source rocks and the transport of clastic materials from high-aluminum source rocks. The source rocks were closely associated with intermediate-acidic magmatic rocks and potentially related to the weathering of Ordovician carbonates.

Distribution Characteristics of Trace Elements in Carboniferous–Permian Coal from the Western Margin of Ordos Basin: Emphasis on Their Complex Geological Genesis

The Carboniferous–Permian coal deposits in the western margin of the Ordos Basin are known for their unique geological characteristics and potential enrichment of trace elements; however, there have been limited studies on the complex geological genesis of these elements, hindering the development of effective strategies for mineral resource exploration in this region. This study aims to investigate the distribution characteristics of trace elements in Carboniferous–Permian coal from the western margin of Ordos Basin, focusing on their complex geological genesis using techniques such as optical microscopy, X-ray fluorescence spectrometry, and inductively coupled plasma mass spectrometry. The results show that the average maximum vitrinite reflectance values in the Helanshan coalfield, Zhuozishan coalfield, and Ningdong coalfield are 1.25%, 0.83%, and 0.69%, respectively. Compared with the world’s hard coals, Li and Ga in Carboniferous–Permian coal from the western margin of the Ordos Basin are mildly enriched (CC, concentration coefficients; 2 &lt; CC &lt; 5) or enriched (5 &lt; CC &lt; 10). On the basis of revealing the response of the geochemical characteristics of coal to the geological development of the basin, the composite genetic model of terrigenous clastic supply, fault structure, low-temperature hydrothermal fluid and coal metamorphism have been established in Carboniferous–Permian coal in the western margin of the Ordos Basin. In this complex genetic model, folds and faults are very well developed. Although the provenance may have provided sufficient detrital sources for the study area, frequent tectonic changes, denudation, or scour led to the loss of detrital supply, and the provenance did not ultimately cause the enrichment of elements in the study area. However, the widely developed fault structure provided channels for sulfur-containing hydrothermal fluids, and the increase in coal metamorphism resulted in the enrichment of trace elements in the Carboniferous–Permian coal in the western margin of the Ordos Basin.

The Black Hours: Material and Conservation Study, Part 1

ABSTRACT The Book of Hours of Galeazzo Maria Sforza, V. Duke of Milan (Vienna, Austrian National Library, Codex 1856), the so-called Black Hours, is a Flemish illuminated manuscript with silver and gold ink on black coloured parchment from the third quarter of the fifteenth century. The severe deterioration of the parchment by the black colourant resulted in brittleness and numerous losses. This paper describes the history of the manuscript and previous interventions. The condition of the various materials was assessed and put in context with the other six black manuscripts that have been preserved worldwide. The fibre morphology, the hydrothermal stability and the investigation of the fibre structure in the Scanning electron microscope confirmed the degradation of the parchment fibres. The black colourant was identified as iron gall ink by X-ray fluorescence spectrometry (XRF) and Raman spectroscopy. The elemental composition of silver and gold was analysed with XRF. Based on these results, a model conservation treatment and a new preservation solution were developed.