X-ray Fluorescence Analysis Research Articles

Investigating the oxidation behavior of Mg-Zn alloy: Effects of heating rates, gas flow, protective atmosphere, and alloy composition

Magnesium-zinc alloys offer promising lightweight properties but are prone to oxidation during high-temperature processing and usage. In this study, the oxidation behavior of Mg-Zn alloy was examined according to the inert gas type flow rate, heating rate and alloy amount. Initially, alloys were produced by adding zinc at weight percentages of 0.5%, 1.5%, and 2% using the casting method. The alloys were characterized using X-ray fluorescence (XRF), X-ray Diffraction (XRD), and scanning electron microscope (SEM) analyses, revealing the formation of dendritic Mg-Zn intermetallic within the alloy. The oxidation behavior of these alloys was examined via differential thermal analysis (DTA) and thermogravimetric analysis (TGA), considering factors such as heating rate, gas flow rate, type of protective atmosphere, and amount of alloying element. The results indicated that the onset temperature of oxidation decreased with increasing heating rate. The effect of gas flow rate varied depending on the heating rate and the type of gas. Under a nitrogen atmosphere, conditions with a heating rate of 20°C∙min‒1 and a gas flow rate of 5 cm3∙min‒1 resulted in the least oxidation. In an argon atmosphere, a gas flow rate of 5 cm3∙min‒1 was found to be sufficient to prevent oxidation. However, at a gas flow rate of 1 cm3∙min‒1, a heating rate of 20°C∙min‒1 was more effective in preventing oxidation. The alloying element (zinc) likely reduced oxidation, particularly at the 1.5% addition level, possibly due to the formation of intermetallic compounds.

Malachite green dye removal with aluminosilicate nanopowder from aluminum dross and silicomanganese slag

Malachite green is a persistent, bioaccumulative, mutagenic, carcinogenic, and teratogenic dye that poses significant risks in water sources, making its removal from water a critical necessity. This study aims to fabricate a sorbent comprising amorphous aluminosilicate nanopowder utilizing silicomanganese slag (SMS) and secondary aluminum dross (SAD) waste materials to remediate dye-contaminated water. The silica and alumina components of the SMS and SAD were extracted as sodium silicate and sodium aluminate leachates, respectively, through an effective hydrometallurgical conversion process. An empirical formula of Al2O3·2.3SiO2 was deduced from the X-ray fluorescence analysis of the synthesized material. The X-ray diffraction (XRD) pattern indicated the amorphous nature of the synthesized aluminosilicate, with no evidence of nanocrystals or ordered clusters observed via high-resolution transmission electron microscopy (TEM). Based on TEM micrographs, the aluminosilicate particles ranged in size from 20 to 80 nm. The synthesized aluminosilicate nanopowder was utilized to treat wastewater containing malachite green dye, demonstrating a remarkable dye removal efficiency of 97% after a 15-min contact time using 30 mg of adsorbent in a 30 mL dye solution at 200 rpm. The methodology proposed in this study could facilitate the production of amorphous aluminosilicate powder as a high-value product from industrial waste. Studies on its reusability demonstrated that it could remove over 90% of the dye after three cycles of use.

Effects of soil and phylogeny on sulfur and phosphorus concentrations in wild plants on volcanic and non-volcanic soils in Japan

ABSTRACT Andosols are soils characterized by relatively high sulfur concentrations, but also by their low phosphorus availability for crops and vegetables. We assessed the effect of soil type on the concentrations of sulfur and phosphorus in plants using handheld X-ray fluorescence (XRF) analysis on herbarium specimens collected from Andosols and non-volcanic soils in Japan. The sulfur concentrations in plants from Andosols were higher than plants from non-volcanic soils, but there was no significant difference between their foliar phosphorus concentrations. Only three specimens out of 1203 herbarium specimens were below the sulfur concentration (1000 mg kg−1) needed for adequate growth of crops, but about half of specimens were below that for phosphorus (2000 mg kg−1). The sulfur concentrations were high in herbaceous plants, especially in plants from the Brassicaceae and Liliaceae families. Overall, the results show that the sulfur concentrations in wild plants from Japan were higher in Andosols, with a low risk for sulfur deficiency. In contrast, the effect of soil type on the phosphorus concentrations in plants was small, and this may be explained because most wild plants grow under phosphorus-limiting conditions. Finally, the analysis reveals a strong correlation between sulfur and phosphorus concentrations in plants, suggesting the existence of a mechanism that controls the sulfur and phosphorus concentration ratios.

Improving the accuracy of density logging results considering mineral composition for evaluation of high-level radioactive waste disposal sites

ABSTRACT Site selection and characterisation are key factors influencing the safe, stable disposal of spent nuclear fuel. Site selection can be based on geophysical surveys, and geophysical well logging is performed at the detailed survey stage. Typically, gamma – gamma density logging is conducted to continuously obtain in situ density information regarding the well depth. However, gamma – gamma density logging is often influenced by the geological characteristics of the site. The ratio of atomic number to atomic weight is required to convert the electron density obtained through density logging counts into bulk density. Because it is difficult to calculate these ratios for the entire depth, an equation based on water-filled limestone is typically used for conversion. Therefore, as the difference in the ratio of the atomic number and atomic weight increases relative to that of limestone, the difference between the converted bulk density and the actual bulk density increases. In this study, equations were derived for various mineral compositions and applied to the density logging results. Matrix density was analyzed using a pycnometer, and the ratio between the atomic number and weight was calculated according to X-ray fluorescence analysis results. This approach improved the accuracy of the density logging data and reduced density errors. The proposed method is expected to be particularly useful for estimating in situ density at high-level radioactive waste disposal sites without complex geological formations.

Influence of construction materials on the natural mummification process: case study of the municipal pantheon of Santa Paula, Guanajuato, Mexico.

The process of natural or spontaneous mummification has been observed for more than a hundred years in various Mexican pantheons. The construction materials used in the niches of the pantheons generate particular microenvironmental conditions that promote the preservation of organic materials. The construction materials (mining adobe, brick and stone material) that make up the three series of the municipal pantheon of Santa Paula were studied and analyzed using X-ray Diffraction, X-ray Fluorescence and petrographic analysis techniques. At the same time, the mechanical and physical properties of the materials were determined, as well as the relative humidity and temperature within the niches. The results indicate that the geochemistry, distribution and percentage of said materials inside of the niches created exceptional microclimatic conditions that favored the conservation of the bodies. With this contribution we intend to advance the understanding of the influence that construction materials had on the process of natural mummification.

Bentonite Clays Related to Volcanosedimentary Formations in Southeastern Spain: Mineralogical, Chemical and Pozzolanic Characteristics

The volcanism that took place during the Neogene in the southeastern Iberian Peninsula caused a large accumulation of volcanosedimentary materials, which were subsequently altered and transformed into bentonite deposits. The mineral composition and technical quality of these deposits have been demonstrated and established in this work. The main object of this research is the mineral, chemical and thermal characterization of the bentonites that lie in the southeastern region of Spain and to demonstrate their technical capabilities to be used as pozzolans. The first phase of characterization of the samples was carried out by X-ray diffraction (XRD), oriented aggregates (OAs), X-ray fluorescence (XRF) and thermogravimetric analysis (TGA). In the second phase, a chemical–technical quality test (CTQT) was carried out, aimed at determining reactive SiO2 and reactive CaO, whereas in the third phase, a chemical pozzolanicity test (CPT) was carried out to establish the pozzolanic behavior of the samples over two test periods: 8 and 15 days. The XRD and OA analyses showed that the bentonite samples are made up of a main phase formed by montmorillonite, quartz, plagioclase-albite and chabazite–Ca. The results obtained by XRF on the bentonite samples indicated that the SiO2 contents are high and vary between 43.33% and 64.71%, while Al2O3 ranges between 15.81% and 17.49%. The CTQT established that more than 80% of the SiO2 and CaO present in the samples are reactive, which was confirmed by the results of the chemical pozzolanicity test (CPT). The results obtained show that the bentonites in this study present technical qualities that are undoubtedly reinforced by their mineral constitution and chemical composition. These tests could become a practical guide for the selection of eco-efficient materials in the production of pozzolanic cements and environmentally friendly ceramic products.

Experimental characterization of two clay deposits blended with feldspar and quartz for building services and refractory applications

Clay deposits across the globe have variations in mineralogical compositions that elicit their use in numerous applications. In this study, two clay deposits were identified and blended with feldspar and quartz in various amounts to produce different samples of composites that could be used for applications in building services and refractories. Chemical analysis, mineralogical composition, microstructure, physical properties, and thermal behaviours were characterized. The X-ray fluorescence (XRF) analysis results show that the clays belong to the aluminosilicate group containing traces of other oxides which enhance strength and the crystallization of thermally stable phases. The XRD patterns confirmed the presence of dominant quartz with moderate to minor presence of kaolin, orthoclase, and albite. The texture of the clays showed particles of different sizes and shapes with uneven distribution. The EDX characteristic spectrum showed x-ray characteristic peaks of Si, Al, Fe, K, and O which affirmed their major oxide compositions. Physical properties results show that firing at various temperatures and blending resulted to increase in Bulk density and flexural strength while apparent porosity and water absorption decreased. The TGA, DTA, and DSC results show that the two clay minerals are thermally stable. This can be attributed to the nucleation and crystallization of refractory phases like cristobalite and mullite. Addition of feldspar and quartz was found to contribute significantly to improve the overall properties of the investigated clays. A comparison of the various results from the two clay deposits suggests that they could be suitable for building services and refractory applications.

Exploring Degradation in PEM Water Electrolysis Cells Due to Metal Migration: Insights from X-Ray Fluorescence Analysis

Green hydrogen production through proton exchange membrane (PEM) water electrolysis offers a viable renewable energy storage and transport solution. The Hydrogen Evolution Reaction (HER) and the Oxygen Evolution Reaction (OER) are central to this technology, with the latter’s slow kinetics posing a significant bottleneck. Despite research efforts, iridium (Ir) is the only element which currently meets the stability and activity needs of OER, challenging the search for alternatives and shifting focus towards enhancing catalyst stability [1]. Recent studies have identified metal migration, particularly of Ir, as a critical factor in the degradation of PEM water electrolyzers [2]. This finding has highlighted the importance of understanding metal migration mechanisms and the need to investigate the contribution or interaction of less studied elements such as platinum (Pt), titanium (Ti), and iron (Fe) to the degradation process.This study investigates the migration of both catalytically active (Ir, Pt) and inactive (e.g., Ti, Fe, Ca) metals within PEM water electrolysis membranes, using ex-situ 2D X-ray fluorescence (XRF) mapping (s. Fig. 1). Tests were conducted on PEM water electrolysis single cells (active area: 4 cm2) with a NafionTM 115 catalyst-coated membrane, with anode and cathode loadings of 2.0 mgIr/cm2 and 1.0 mgPt/cm2, respectively. The study entailed varying operating times (10 h, 100 h, 500 h, 1500 h) under constant load, different load profiles (e.g., open-circuit voltage (OCV) and accelerates stress test (AST) phases) for 500 h, and the introduction of specific impurities like iron (Fe) and calcium (Ca) through the anodic feed water. Complementary ICP-MS analysis of the anode and cathode waters was also performed. Selected segments of the catalyst-coated membranes (CCMs) were investigated using synchrotron radiation-based XRF at microXAS beamline (X05LA) of the Swiss Light Source (Paul Scherrer Institute, Villigen, Switzerland) at 11.0, 11.4, and 11.7 keV (below and above the Ir L3- and Pt L3-edges, for IrO2, see e.g. ref. [3]). The beam was focused using a Kirkpatrick-Baez (KB) mirror system. The spatial resolution of the measurements was approx. 1 μm, allowing selective identification and relative concentration of elements to be mapped within the entire cell cross-section (electrodes and polymer layer).Through our XRF analysis, it is possible to detect migration of the catalytically active materials (Ir, Pt) through the Nafion membrane depending on the degradation time. Interestingly, while impurity tests with Ca led to its accumulation in the membrane, Fe impurities introduced similarly did not show significant accumulation. These results, demonstrating the intricate details of metal migration and their varying behaviors under different operational conditions, underscore the value of high-resolution XRF mapping with synchrotron radiation in providing critical insights. This understanding is vital to unraveling the complex degradation mechanisms of PEM water electrolyzers. Further experiments may in principle allow for precise quantification of metal migration, with measurement of appropriate elemental standards. Figure 1. Schematic overview of the study: Catalyst-coated membranes (CCMs) at various stages of degradation are investigated using synchrotron radiation-based X-ray fluorescence (XRF) mapping. This method provides a 2D elemental distribution map, as demonstrated with Iridium (Ir) in this example. Analysis of the cross-sectional distribution of the element within the membrane allows for inferences regarding its migration. We thank the SLS for providing beam-time through an accepted proposal (20221749) and appreciate the micro-XAS beamline team’s help during measurements and data processing.

Pt/C and PtRu/C Catalysts Prepared by Modified Sulfite Complex Routes for Fuel Cell Applications

In-house 30 wt.% Pt and 50 wt.% Pt1Ru1 catalysts supported on high-surface area carbon (Ketjenblack, abbreviated as KB) were synthesized by the sulfite complex route. Two different procedures involving either a direct mixing of Pt-sulfite and Ru-sulfite complexes or Pt-sulfite preparation and subsequent impregnation of Ru precursor were adopted for the bimetallic species. In both cases, an impregnation of the formed metal oxides onto KB was adopted to increase the electronic conductivity of the samples. Finally, a carbothermal treatment at 600°C in He atmosphere was carried out for the reduction of the metal oxides to metallic PtRu/C compounds. The Pt1Ru1 ratio was calculated and revealed by X-ray fluorescence (XRF) analysis whereas the carbon percentage was calculated by weight loss. 50 mg of sample was treated in air at 550°C for 2 h and, after cooling, the weight corresponded to 25 mg, confirming a carbonaceous matrix percentage of 50 wt.%. In a similar way, the 30 wt.% Pt/C was determined. X-ray diffraction (XRD) revealed that the samples showed face centered cubic (fcc) structure for Pt nanoparticles. It appears that two distinct crystallographic phases of Pt and Ru nanoparticles were encountered after the synthesis conducted by Ru impregnation. In contrast, only a single fcc phase is visible when the Pt and Ru sulfite precursors were mixed, confirming the formation of an alloy. Furthermore, Scanning Transmission Electron Microscopy-Energy dispersive X-ray spectroscopy (S/TEM-EDX) and X-ray Photoelectron Spectroscopy (XPS) were used to characterize the differences in morphology and surface characteristics of the catalysts.For the electrochemical measurements, rotating disc electrode (RDE) technique under acid and alkaline conditions was employed to investigate the half cell reactions. The catalysts were also deposited at the anode and cathode of fuel cells to evaluate the activity, performance, and short-term durability. Acknowledgement “This research was funded by the European Union – EIT Raw Materials in the framework of the following project: LYDIA- Recycling Critical Metals from Fuel Cells (G.A. 22019)”

Evaluating thermal activated coal gangue as alternative filler in asphalt binder using rheological experiments and molecular dynamic simulation

Asphalt mastic, an important raw material in asphalt pavement, is a mixture of asphalt binder and mineral filler. This study utilized coal gangue (CG) as alternative of natural filler in asphalt mastic, which has benefits to recycling solid waste and saving non-renewable resource. In order to achieve performance improvement of CG asphalt mastic (CGAM), thermal activation approach was applied to treat CG particles from 450 ℃ to 900 ℃. Before and after treatment, the surface morphology, mineral components and size distribution were characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF) and laser particle size analyzer. Meanwhile, the dynamic shear rheometer (DSR) and bending beam rheometer (BBR) experiments were conducted to compare the rheological responses of CGAM at high and low temperatures. Further, the interfacial behavior between asphalt binder and CG filler is simulated by molecular dynamic (MD) method, aiming to explore the interaction mechanism at atomistic scale. Results show that the activated CG possesses a smaller particle size and a rougher surface by comparison in virgin one (i.e., unactivated CG). And the calcination process results in the crystal phase transition of CG and the proportion increase of alkali minerals, contributing to the stronger interaction ability and higher adhesion energy with asphalt binder. Owing to the positive changes of CG during calcination process, the corresponding CGAM exhibits superior deformation resistance property under recycling loads at high temperature and flexural creep ability at low temperature, especially when the calcination temperature rises to 750 ℃.

Low-Cost and Eco-Friendly Calcium Oxide Prepared via Thermal Decompositions of Calcium Carbonate and Calcium Acetate Precursors Derived from Waste Oyster Shells.

Waste oyster shells were utilized to produce calcium carbonate (CaCO3) by grinding. This CaCO3 was then reacted with acetic acid to yield calcium acetate monohydrate (Ca(CH3COO)2·H2O). Both CaCO3 and Ca(CH3COO)2·H2O were used as precursors for synthesizing calcium oxide (CaO) through thermal decomposition at 900 °C and 750 °C, respectively. The yields of CaO from both precursors, determined through calcination experiments and thermogravimetric analysis (TGA), exceeded 100% due to the high purity of the raw agents and the formation of calcium hydroxide (Ca(OH)2). X-ray fluorescence (XRF) analysis revealed a CaO content of 87.8% for CaO-CC and 91.5% for CaO-CA, indicating the purity and contamination levels. X-ray diffraction (XRD) patterns confirmed the presence of CaO and minor peaks of Ca(OH)2, attributed to moisture adsorption. Fourier-transform infrared (FTIR) spectroscopy identified the vibrational characteristics of the Ca-O bond. Scanning electron microscopy (SEM) showed similar morphologies for both CaO-CC and CaO-CA, with CaO-CA displaying a significant amount of rod-like crystals. Based on these results, calcium acetate monohydrate (CA) is recommended as the superior precursor for synthesizing high-purity CaO, offering advantages for various applications.

Quantifying pyrrhotite superstructures in copper-gold ore flotation through synchrotron X-ray diffraction analysis

Pyrrhotite, a significant sulfide mineral in base metal sulfide deposits, exists in various superstructures including magnetic (4C) and non-magnetic (5C and 6C) types. Identifying and quantifying pyrrhotite superstructures in an ore sample has been a challenge, hindering efforts to improve pyrrhotite rejection in copper–gold flotation. This study employed synchrotron X-ray powder diffraction (S-XRPD) analysis to quantify pyrrhotite superstructures in the concentrates obtained from flotation of a copper–gold ore after grinding with forged steel and 30% chromium grinding media. S-XRPD demonstrated a superior capability in detecting characteristic peaks of 4C, 5C and 6C pyrrhotite superstructures compared to conventional XRPD. Utilizing the Rietveld refinement method, the identified pyrrhotite superstructures were quantified. These findings were successfully validated through independent X-ray fluorescence analysis on elemental compositions. The quantification work demonstrated that 30% chromium grinding media enhanced the floatability of all pyrrhotite superstructures over forged steel grinding media and each pyrrhotite superstructure in the copper–gold ore resembled a copper sulfide mineral rather than pyrite in response to grinding media during flotation. This research highlights the potential of S-XRPD as an effective technique for identifying and quantifying pyrrhotite superstructures in ore samples and determining their flotation behaviors.

Effect of magnesia additive on the morphology and physico‐mechanical properties of kaolinitic clays ceramics

AbstractNigeria is rich in various minerals, including crude oil and solid minerals. However, despite this abundance, effectively utilizing these resources remains a challenge. Kaolin, also known as white China clay, is a crucial raw material used in industries such as ceramics, paper, paint, plastic, and welding electrodes. Despite its plentiful availability in Nigeria, kaolin has not been adequately exploited. Consequently, Nigeria spends approximately 14.35 million USD annually to import refined kaolin to meet local demand, due to the lack of capacity to process it to the required industrial standards. This study investigates the effect of magnesia (MgO) on the morphology and physico‐mechanical properties of kaolinitic clay ceramics using the slip‐casting method. Various analytical techniques were employed to examine the kaolin, including X‐ray fluorescence (XRF), X‐ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), and Scanning Electron Microscopy (SEM). Also, compressive and flexural tests were conducted. The XRF analysis revealed that all samples contained SiO2 (54.41%wt), Al2O3 (34.05%wt), and other trace elements. The main mineral phases identified were quartz, microcline, and orthoclase. Among the samples, 30–200 exhibited the highest compressive strength at 218 MPa, while the highest flexural rigidity was observed in sample 15–200. The results indicated that MgO significantly affected the properties of kaolin, as the control sample had a compressive strength of 59 MPa. The study also found that the quantities of additives should align with stoichiometric requirements. Results showed hypo‐stoichiometry in samples 30–600 and 15–400, and hyper‐stoichiometry in sample 60–200. XRF, XRD, and FTIR spectra confirmed the elemental and chemical compositions of the samples, while SEM analysis revealed the morphological structure. It was observed that increasing the magnesia content from 10% to 30% led to an increase in pore spaces within the samples. TGA analysis provided insights into the relationship between mass loss and temperature variation in the ceramic samples, While The DTG curves explain the endothermic phase changes over changes in temperature; at 50–150°C, loss of the water phase is complete, at 300–400°C burning of organic matter phase is achieved and at 500–700°C endothermic dihyroxylation phase begins forming armorphous meta‐kaolin.

Mechanical properties of polymer composite films with ZnO nanoparticles synthesized in low-temperature plasma under ultrasonic cavitation

Abstract In this study, polymer nanocomposite materials consisting of the copolymer of ethylene and vinyl acetate as a matrix and nanoparticles of zinc oxide as a filler have been obtained and examined by physicochemical and mechanical methods. Zinc oxide nanoparticles used in this study were fabricated using the plasma discharge under the effect of intensive ultrasonic cavitation. To ensure that resulting nanocomposites will acquire homogeneous distribution of filler nanoparticles, solution technology was utilized followed by the melt compounding technique, and also nanoparticles treated and non-treated with ultrasound were applied. The fabricated samples of nanocomposite material films were examined by X-ray phase analysis, then X-ray fluorescence analysis as well as scanning electron microscopy. The differences between the samples were demonstrated: when the nanoparticles without ultrasonic treatment were used, the particles were found to be more strongly aggregated within the bulk of the composite material and the average size of particles was visually larger in comparison to the sample filled with nanoparticles subjected to ultrasonic action. Finally, studies of the tensile strength and relative deformation of the samples were carried out. From the results of mechanical tests, it can be seen that, according to both studied parameters, there is an optimal concentration of ZnO nanoparticles. For tensile strength, the highest result was obtained at a concentration of nanoparticles of 3%, and for the relative elongation to rupture of the sample, the highest value was achieved at a concentration of nanoparticles of 2%.

CHARACTERIZATION AND MINERALOGICAL ANALYSIS OF EZEAGU IRON ORE, ENUGU STATE, NIGERIA

An investigation was conducted on the characteristics and mineralogical analysis of Ezeagu iron ore. Ezeagu is situated in the Ezeagu Local Government Area of Enugu State with its administrative headquarters located in the town of Aguobu-Owa. The characterization and mineralogical analysis were conducted by utilizing some basic techniques for analysis such Scanning Electron Microscopy (SEM attached with Energy Dispersive X-Ray Spectroscopy (EDX), X-ray fluorescence (XRF), and an X-ray diffractometer (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). These analytical techniques were used to determine all the necessary parameter for this research work. The XRF, XRD, EDX, and FTIR analyses performed on the iron ore revealed that it is a high-grade, high-silica, and low-alumina ore with a predominantly hematite mineralogy. The ore's average composition consists of 30.59% SiO2, 2.11% Al2O3, 53.75% Fe2O3, and minor amounts of other oxides. The XRD analysis showed the presence of other oxides such as TiO2, MnO, MgO, and Na2O in the ore sample. The EDX analysis indicated that the ore is predominantly composed of iron, with smaller amounts of titanium, manganese, and silicon. FTIR analysis identified functional groups such as Fe-O, Fe-OH, and Fe-H bonds, which are typical for iron oxides and hydroxides

ZnO/TiO2 photocatalytic nanocomposite for dye and bacteria removal in wastewater

This study investigates ZnO/TiO2 nanocomposites synthesized by the sol–gel method for their potential application in textile wastewater treatment. The physicochemical properties of these materials were comprehensively characterized using various analytical techniques, including transmission electron microscopy (TEM), x-ray diffraction (XRD) analysis, x-ray fluorescence (XRF) spectroscopy, Brunauer–Emmett–Teller (BET) surface area analysis, and UV–visible (UV-Vis) spectroscopy. XRD and XRF analyses confirmed the formation of a ZnO/TiO2 heterostructure. TEM images revealed a quasi-spherical morphology with slight agglomeration. The ZnO/TiO2 nanocomposite with a 1:5 molar ratio of Zn(II):Ti(IV) showed the highest BET surface area (91.345 m2 g−1) and the narrowest band gap (Eg = 3.06 eV). This composite demonstrated efficient degradation of methylene blue dye under sunlight irradiation and exhibited 100% antibacterial activity against S. typhi and S. aureus at concentrations ≥5 mg ml−1, indicating its potential for treating textile wastewater.

Novel silica coated trimetallic ferrite functionalized with amino acid-based protic ionic liquid (Mn0.5Fe0.25Ca0.25Fe2O4-SiO2@[L-Tyr][HSO4]): A versatile bio-nanostructure to catalyze green synthesis of poly-substituted hydroquinolines and pyrido[2,3-d]pyrimidine-triones

In this research a magnetized inorganic-bioorganic nanocomposite prepared through coating the Mn0.5Fe0.25Ca0.25Fe2O4 core by silica layer, and consequent functionalization by the L-tyrosinium hydrogen sulfate ionic liquid. The structure of the hybrid nanocomposite (Mn0.5Fe0.25Ca0.25Fe2O4-SiO2@[L-Tyr][HSO4]) studied by density functional theory (DFT) calculations which contains L-Tyr protonation step and the chemisorption of L-Tyr cation on silica layer. The novel synthesized bio-nanocomposite (Mn0.5Fe0.25Ca0.25Fe2O4-SiO2@[L-Tyr][HSO4]) characterized by Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDAX), vibrating-sample magnetometery (VSM), thermogravimetric (TGA/DSC), X-ray powder diffractometery (XRD), X-ray fluorescence (XRF), and transmission electron microscopy (TEM) analysis. The hybrid bio-nanocomposite applied for solvent-free diastereoselective synthesis of dispiro[tetrahydroquinoline-bis(2,2-dimethyl[1,3]dioxane-4,6-dione)] derivatives via one-pot pseudo eight-component reaction of meldrum’s acid, aromatic aldehydes, and arylamines at 50 °C. Also, the bio-nanocatalyst utilized for the aqua-mediated green synthesis of 5-aryl-5,6-dihydropyrido[2,3-d]pyrimidine-2,4,7(1H,3H,8H)-triones at 70 °C through the reaction of meldrum’s acid, aryl aldehydes, and 6-aminouracil. The recovery and reusability of the bio-nanohybrid also examined within 2 runs successfully.

Evaluation of the use of polyvinyl alcohol in the manufacture of pressed samples for X-ray fluorescence analysis

The reliability of the results of X-ray fluorescence analysis (XRF), which is widely used in determination of the elemental composition of various materials, largely depends on the quality of sample preparation. When producing pressed tablets for X-ray fluorescence analysis of trace elements, a binder is often used in a powder form, which requires significant time for thorough homogenization. We present the results of applicating a polyvinyl alcohol solution as a binder in the manufacture of pressed samples without using a substrate in determination of microelements by XRF. The parameters for obtaining a durable tablet with a homogeneous composition that matches the condition of minimum impact on the intensity of the analytical lines of the elements being determined are presented. It is shown that the optimal sample weight for the proposed method of producing pressed tablets is 7 g with the addition of polyvinyl alcohol in a ratio of 7:1, the optimal drying time for the tablet after pressing is 1 hour. The calculated variation coefficients of the analytical signal (<2%) indicate the homogeneity of the produced tablets. The maximum values of standard deviations of pressed tablets for the selected ranges of elements are much less than acceptable, which confirms the validity of the proposed method of sample preparation. It is also shown that during long-term storage and repeated measurements, pressed tablets with the polyvinyl alcohol solution retain their original structure and intensity of analytical lines of elements. The accuracy of measurements in the subsequent determination of rock-forming elements is consistent with their certified contents. The results obtained can be used to reduce the time spent on getting a representative pressed sample when using polyvinyl alcohol, determining elements without additional support (coating films), microelement and silicate analyzes from one sample.

Determination of S, Ni, Cu in copper-nickel sulfide ores by total reflection X-ray fluorescence analysis: experience of participation in the interlaboratory comparisons

The quality of the determination of S, Ni, Cu in copper-nickel sulfide ores was assessed in the framework of the program for interlaboratory comparative tests (ICT) using total reflection X-ray fluorescence analysis (TXRF) taking into account the criteria for methods for determining the chemical composition of mineral raw materials. Certified TXRF techniques for the analysis of mineral materials are absent, so the interlaboratory comparison test was used to control and improve the accuracy of measurements by TXRF. Powdered ore samples were prepared as suspensions by wet grinding: 100 mg of the powder, 4 ml of ultra-pure water and 250 μl of the Ga standard solution were milled using 20 g of ZrO2 balls 1 mm in diameter in the mixing mill for 10 minutes at a frequency of 20 Hz. The ratio of the intensities of the characteristic lines of the analyzed elements and the Ga internal standard was chosen as an analytical signal. To plot calibration curves, a set of ore reference samples was analyzed using certified procedures (atomic absorption spectrometry for Cu, Ni, gravimetry for S). The quality of the TXRF analysis was assessed by the value of Z-criterion. The measurement error did not exceed 5 rel. %. The relative percentage differences between the TXRF results and the results obtained in the interlaboratory study was less than 10%. The described method can be used for rapid analysis of copper-nickel sulfide ores.

Application of Micro X-ray Fluorescence and X-ray Tomographic Analysis of Metal and Actinide Materials

Application of Micro X-ray Fluorescence and X-ray Tomographic Analysis of Metal and Actinide Materials