Energy Dispersive X-ray Fluorescence Research Articles

Laser-based techniques for the non-invasive characterisation of grisaille paints on stained-glass windows

Grisaille was the first paint applied on stained-glass panels, used in Europe since the twelfth century. Historical written sources described the use of iron and copper together with a high lead-silica base glass in the grisailles production. This project aims to study the evolution of the grisaille paint composition throughout time and the changes in the raw materials used in their production using non-destructive and non-invasive techniques. To achieve this objective, 23 grisaille samples dated from the 13th to the twentieth centuries from nine different countries (Portugal, Poland, United Kingdom, Sweden, Norway, Belgium, Low Countries, Germany, and France) were studied by means of micro particle-induced X-ray emission (μ-PIXE), micro energy dispersive X-ray fluorescence (μ-EDXRF), laser-induced breakdown spectroscopy (LIBS), laser-induced fluorescence (LIF), non-linear optical microscopy (NLOM) in the modality of multiphoton excitation fluorescence (MPEF) and optical microscopy (OM). The results showed that it was possible to identify compositional differences and patterns throughout the samples when compared with literature results. The preference for using copper in central and south-central European countries and the addition of new compounds (CoO, Cr2O3, MnO) as colouring agents since the nineteenth century was verified. The LIBS analyses allow the identification of boron on two samples, confirming the change of base glass components since the seventeenth century. The NLOM-MPEF showed the capability of this technique to measure the grisaille paint layers’ thickness. This non-invasive multi-analytical and complementary approach proves itself efficient in identifying changes in the grisaille’s composition throughout time, which can be interpreted as changes in the raw materials and manufacture used in the production of these paint materials.

ASSESSMENT OF ACTIVATED CARBON FROM Cocos nucifera HUSKS-CLAY COMPOSITES IN THE REMOVAL OF METALS FROM AQUEOUS-MEDIA

Varying percentages (0.1, 0.3, 0.5, 0.7, and 0.9 g) of Kono-Boue pure clay (control) and acid activated carbonized Cocos nucifera husk clay composites (AACCHCC) respectively were assessed for their effectiveness in the removal of Cu2+, Cd2+, Pb2+ and Cr2+ from aqueous media by batch adsorption technique using AAS-analyzer. The adsorbents were characterized using Energy-dispersive X–Ray Fluorescence (EDXRF) and Scanning Electron Microscopy (SEM). The adsorption parameters were determined based on optimal conditions of adsorbent dosage (0.90 g), initial adsorbate concentration (10.00 mg/L), pH (7.00), contact time of 60.00 mins (AACCHCC) and 80 mins (control) and at 300 rpm. Optimum percentage adsorptions of 98.29, 88.71, 99.47 and 60.30% respectively were obtained when the control was used as adsorbent and 99.99, 99.93, 99.80 and 86.15% respectively for the AACCHCC. EDXRF showed that AACCHCC was richer in K, Ca, and Ce than the control while SEM showed wider dispersed polycrystallites. Langmuir and Freundlich isotherms used to describe the equilibrium data showed better fits for Langmuir (a monolayer homogenous model) while the kinetic studies fitted the pseudo-second order kinetic better. The study has shown that AACCHCC is a more effective adsorbent with a shorter uptake time of 60 mins than the control.

Comparisons of Spatial and Temporal Variations in PM2.5-Bound Trace Elements in Urban and Rural Areas of South Korea, and Associated Potential Health Risks

PM2.5-bound trace elements were chosen for health risk assessment because they have been linked to an increased risk of respiratory and cardiovascular illness. Since the Korean national air quality standard for ambient particulate matter is based on PM2.5 mass concentration, there have only been a few measurements of PM2.5 particles together with trace elements that can be utilized to evaluate their effects on air quality and human health. Thus, this study describes the trace elements bound to PM2.5 in Seoul (urban area) and Seosan (rural area) using online nondestructive energy-dispersive X-ray fluorescence analysis from December 2020 to January 2021. At both the Seoul and Seosan sites, S, K, Si, Ca, and Fe constituted most of the PM2.5-bound trace elements (~95%); major components such as S, K, and soil (estimatedcalculatedcalculated based on oxides of Si, Fe, Ca, and Ti) were presumably from anthropogenic and crustal sources, as well as favorable meteorological conditions. During winter, synoptic meteorology favored the transport of particles from severely contaminated regions, such as the East Asian outflow and local emissions. The total dry deposition flux for crustal elements was 894.5 ± 320.8 µg m−2 d−1 in Seoul and 1088.8 ± 302.4 µg m−2 d−1 in Seosan. Moreover, potential health risks from the trace elements were estimated. Cancer risk values for carcinogenic trace elements (Cr, As, Ni, and Pb) were within the tolerable limit (1 × 10−6), suggesting that adults and children were not at risk of cancer throughout the study period in Seoul and Seosan. Furthermore, a potential risk assessment of human exposure to remaining carcinogens (Cr, As, Ni, and Pb) and non-carcinogens (Cu, Fe, Zn, V, Mn, and Se) indicated that these trace elements posed no health risks. Nevertheless, trace element monitoring, risk assessment, and mitigation must be strengthened throughout the study area to confirm that trace-element-related health effects remain harmless. Researchers and policymakers can use the database from this study on spatial and temporal variation to establish actions and plans in the future.

Phytochemical Composition of Combretum molle (R. Br. ex G. Don.) Engl. & Diels Leaf and Stem Extracts.

The demand for medicinal plants is on a rise due to their affordability, accessibility and relatively non-toxic nature. Combretum molle (Combretaceae) is used in African traditional medicine to treat a number of diseases. This study aimed to screen the phytochemical composition of the hexane, chloroform and methanol extracts of C. molle leaves and stems using qualitative phytochemical screening. Additionally, the study aimed to identify the functional phytochemical groups, determine the elemental composition and provide a fluorescence characterization of the powdered leaves and stems by performing Fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray (EDX) microanalyses and fluorescence microscopy. Phytochemical screening revealed the presence of alkaloids, flavonoids, phenolic compounds, polyphenols, terpenoids, tannins, coumarins, saponins, phytosterols, gums, mucilage, carbohydrates, amino acids and proteins within all leaf and stem extracts. Lipids and fixed oils were additionally present within the methanol extracts. FTIR demonstrated significant peaks in absorption frequency in the leaf at wavelengths of 3283.18, 2917.81, 1617.72, 1318.83, 1233.97, 1032.32 and 521.38 cm-1, and in the stem at 3318.91, 1619.25, 1317.13, 1032.68, 780.86 and 516.39 cm-1. These corresponded to the functional groups of chemical compounds including alcohols, phenols, primary amines, alkyl halides, alkanes and alkyl aryl ethers, corroborating the presence of the detected phytochemicals within the plant. EDX microanalyses showed the elemental composition of the powdered leaves (68.44% C, 26.72% O, 1.87% Ca, 0.96% Cl, 0.93% Mg, 0.71% K, 0.13% Na, 0.12 % Mn and 0.10% Rb) and stems (54.92% C, 42.86% O, 1.7% Ca, 0.43% Mg and 0.09% Mn). Fluorescence microscopy provided a characteristic evaluation of the plant in its powdered form and revealed distinct colour changes in the material when treated with various reagents and viewed under ultraviolet light. In conclusion, the phytochemical constituents of the leaves and stems of C. molle confirm the suitability of this species for use in traditional medicine. The findings from this study suggest the need to validate the use of C. molle in the development of modern medicines.

Application of X-rays to interpret alloying effects on the 3d and 4s4p electron populations of nickel-boron-nitrogen metal matrix composites

For this experiment, nickel-boron and nickel-boron-nitrogen alloys are created using the electrochemical deposition method. Utilizing energy-dispersive X-ray methods, the nickel-boron and nickel-boron-nitrogen alloys are characterized. X-ray diffraction was used to examine the crystal structure of nickel-boron and nickel-boron-nitrogen alloys. An energy dispersed X-ray fluorescence spectrometer is used to gather X-ray photons from the present samples. The number of radiated X-ray photons from the present specimens is used to compute the Kβ/Kα intensity ratios. The theoretical Coulomb and Babushkin gauges are used to calculate the populations of the 3d and 4s4p electrons. The observed data imply that shielding effects from 4s3d orbitals, hybridization, changes in energy levels, and charge transfer mechanism may be the causes of the variance in 3d and 4s4p electron populations. In an effort to clarify the conclusions drawn as a result of all these computations, this study contrasts the results with those of pure nickel.

A First Approach to the Study of Winsor & Newton’s 19th-Century Manufacture of Madder Red Lake Pigments

This paper focuses on the first investigation of the 19th-century manufacture of red lake pigments obtained from madder by Winsor & Newton (W&N), prominent artists’ colourman at that time. The first approach to their manufacture was carried out by studying the madder entries of the company’s book P1, found in the W&N 19th Century Archive Database. Eleven production records were discovered under names such as Rose Madder, Madder Carmine, Madder Lake and Madder Rose. Three main methods of synthesis were identified and reproduced, revealing three main steps: washing of the madder roots (Rubia tinctorum L.); extraction in acid media and complexation with Al3+ using alum; and precipitation by the addition of salts such as ammonium carbonate and sodium borate. The syntheses were followed by UV-VIS spectroscopy, and the pigments were further characterised by colourimetry, Energy-Dispersive X-Ray Fluorescence Spectrometry (XRF), Fourier Transform Infrared Spectroscopy (FTIR) and High-Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD). They all exhibited a rose hue in a highly insoluble aluminate matrix. Although the dye extraction was incomplete, alizarin, purpurin and pseudopurpurin were identified. An analytical comparison with a Rose Madder 19th-century oil paint tube was also performed by micro-FTIR and microspectrofluorimetry. This work intends to be foundational to a systematic study of the W&N’s 19th-century madder colours aiming to contribute new knowledge towards their identification and preservation in heritage objects.

Direct determination of chlorine in the glycerin by-product of biodiesel production: A green approach using energy dispersive X-ray fluorescence spectrometry

Glycerin, by-product of biodiesel, is produced in large amounts and it contains several contaminants, including chorine (due to the neutralization stage using HCl). When using this glycerin as biomass to produce energy, the presence of alkaline chlorides may lead to the formation of corrosive fumes at high temperatures. In this sense, the knowledge of chloride content is important in order to decide the fate of this raw by-product. The direct spectrometric determination of chlorine is an analytical challenge. In this context, energy-dispersive X-ray fluorescence spectrometry provided direct and accurate determination, relying on external calibration based on sample dilution and matrix matching with mixture of pure glycerin and water and using NaCl as the analytical (primary) standard. Method limit of quantification was 50 mg kg−1, with analytical curve up to 1000 mg kg−1 (R2 = 0.9992), and repeatability below 5% were found to be adequate for such application in such highly salty samples (original concentrations at mg g−1). In addition to sample directly analysis, without any previous treatment but homogenization and dilution, not requiring chemical derivatization and the not using of toxic reagents are in consonance to the analytical green chemistry requirements, allowing direct analysis of sample with no chemical derivatization with toxic reagents.

Morphology and Structure Characteristics of the Rare Black-Glazed Porcelains Excavated from the Jian Kiln Site of Song Dynasty

Jian tea bowls are greatly appreciated not only due to their thick and lustrous black glazes, but also their exquisite streaked and mottled patterns. Researches on the firing process and colouring mechanism of typical hare’s fur and oil spot Jian glazes have continuously been carried out in the past decades; however, there are few reports about other scarce types of black-glazed porcelains excavated from the Jian kiln site. In this work, we report on a multi-technique analysis of the surface and cross-sectional structure, phase, morphology and chemical composition of three rare types of Jian tea bowls (tea-dust-glazed ware, grey-glazed ware and pearl-glazed ware) combining optical and spectroscopic methods such as optical coherence tomography (OCT), optical microscopy (OM), Portable energy dispersive X-ray fluorescence spectrometry (XRF), laser-Raman spectroscopy (LRS) and scanning electron microscopy coupled with an X-ray energy dispersive spectrometer (SEM-EDS). Results revealed that the tea dust glaze was one high-temperature iron-based crystalline glaze, and its glaze was characterized by a transparent glass matrix; irregular pits completely or partially filled by TiO2; and that ε-Fe2O3 and residual quartz were randomly distributed all over the surface, which produced the appearance of tea-dust. The grey-glazed porcelain was fired at a lower temperature in the dragon kiln than that of the traditional hare’s fur and oil spot samples, its glaze contained some residual quartz, and anorthite crystals showed a serried distribution along the thickness. The pearl-glazed porcelain was fired through a secondary glazing process via artificial stippling quartz powder. This work provides guidance for the firing process of three rare types of Jian wares and has not only scientific but also cultural profound significance, which reveals the features of their historical heritage.

Microstructure and Strength Parameters of Cement-Stabilized Loess

In this study, cement was used as a component to provide a stabilizing effect in order to evaluate the hardness and stability of loess soil. To evaluate the strength properties of loess soil reinforced with cement, samples with four distinct cement concentrations (3%, 5%, 7%, and 9%) and three distinct curing durations (7, 14, and 28 days) were generated. During a series of tests, the flexural strength, direct shear strength, indirect tensile strength, and unconfined compressive strength were determined. An appropriate cement dosage was found, in addition to a durability index that could be used to quantify the effect of water absorption investigations on cement-stabilized loess. Both of these discoveries were made simultaneously. Scanning electron microscopy (SEM) and energy dispersive X-ray fluorescence spectrometry (XRF) examinations were carried out so that the fundamental mechanics of the materials could be comprehended. The results show that the cohesion of cement-stabilized loess is much more sensitive to structure than the friction angle of the material. The increase in shear strength after remoulding is due to cohesion. The SEM study showed that the cement interacted with the loess particles to produce a thick cement network that successfully covered the voids and boosted the mixture’s strength parameters. The 28-days UCS for the samples containing 7% cement was the greatest, at 3.5 MPa, while the UCS for those containing 9% cement was 4.78 MPa. The highest flexural tensile strength of 1.98 N/mm2 was determined after 28 days. The tensile strength after 7 days in samples containing 3%, 5%, 7%, and 9% cement reached a maximum force of 0.15 MPa, 0.23 MPa, 0.27 MPa, and 0.37 MPa, respectively, and increased with each passing day. To achieve the desired level of strength, it is necessary to adjust the proportion of cement. In addition, as the curing period progressed, we observed an increase in the resistance and stiffness of the cement-stabilized loess due to the interactions that take place between the structure and the mineral composition. It is believed that this event was caused by naturally occurring cementation. As a consequence of this reaction, the production of new cementitious materials takes place. The cation exchange that causes the hydration and pozzolanic reaction that leads to the creation of aggregates and interparticle flocculation is responsible for their production. These findings suggest that cement may be utilised as a simple and effective method of loess stabilization, ultimately resulting in improved performance of the loess. Therefore, this study revealed that cement may considerably enhance the microstructure and strength parameters of loess. This research provides important information on cement-stabilized loess that has ramifications for geotechnical investigation, construction, research, and testing to achieve a successful project.

Effect of sodium hydroxide concentration on EAFS based alkali activated binder

The emission of greenhouse gases primarily CO2 during the production of cement is a substantial global threat. Along with this the disposal of industrial waste is also a key concern due to leachate. In order to lower the emissions and make better use of industrial waste, a novel technology termed alkali-activated binder (AAB) can be a potential alternative to ordinary portland cement. In the past few years, AAB’s have been a phenomenon of remarkable interest to the construction sector because of their exceptional mechanical qualities and sustainability. The selection of the source material is a critical factor to develop AAB’s. This research attempts to utilize the electric arc furnace slag (EAFS) generated from the production of steel through EAF route as the primary precursor. Four different variations of sodium hydroxide (SH) molarity (8, 10, 12, and 14) were used to investigate its effect on the fresh and mechanical properties of EAFS-based AAB. The alkali to binder ratio of 0.40, curing temperature 80 °C, and 85% humidity were used for preparing the AAB. Scanning electron microscopy (SEM), Energy-Dispersive X-ray Spectroscopy (EDX), X-ray fluorescence (XRF), and X-Ray diffraction (XRD), are used for material characterization and for analyzing microstructural development.

Evaluation of the toxicity of textile effluent treated by electrocoagulation

Abstract Textile effluents are complex, making it difficult to choose an effective treatment. The textile effluent toxicity in Lactuca sativa after pulsed current (PC) electrocoagulation (EC) was evaluated in this study. The EC was performed using 304 stainless steel electrodes in batch mode. Parameters monitored included pH, temperature, color, and turbidity. Additionally, the process residue was subjected to energy-dispersive X-ray fluorescence (XFR) to determine the elements present. The process achieved proportional color and turbidity removal ranging from 97 to 99% and from 74 to 85%, respectively. Chemical oxygen demand (COD) and total nitrogen removal were 81 and 49%, respectively, in a 50 min time-lapse. The process generated approximately 1.7 kg of solid residue/m3 treated effluent. The XFR results revealed the presence, mainly, of Fe, Cr, and Ni ions in the residue, as well as chlorine. The germination index (GI) and relative growth values showed that EC reduced effluent toxicity slightly, indicating the need for complementary treatment.

Chamotte Clay: A Natural Adsorbent for Separation and Preconcentration of Aluminium

The adsorption behavior of aluminium ions on chamotte clay has been studied in this study. Chamotte clay has been used for the first time for determination of trace levels of aluminium in aqueous solutions. Quantitative adsorption and recovery of aluminium were both rapid and reached an equilibrium in 30 minutes. Aluminium was detected based on the formation of the highly fluorescent Al(III)-morin complex. Two linear calibration graphs were obtained in the range of 0.5-10 µg L-1 and 10-100 µg L-1 with the detection limits of 0.12 µg L-1 and 1.12 µg L-1, respectively. Chamotte clay was characterized by scanning electron microscope coupled with energy-dispersive X-ray spectroscopy, energy dispersive X-ray fluorescence and X-ray photoelectron spectroscopy techniques. Different isotherm models were evaluated and the results showed that the adsorption study was fitted to Freundlich isotherm and a favorable and multilayer adsorption of aluminium was occurred on the heterogeneous surface of the chamotte clay. Thermodynamic and kinetic parameters of aluminium adsorption were also investigated. Various experimental parameters were optimized and the method has been applied to tap and bottled drinking water samples and quantitative recoveries were obtained. The results demonstrated that the chamotte clay, as a natural clay, was expected to be a promising adsorbent for the determination and preconcentration of the trace levels of analyte in real samples.

Correlation Between Toxic Elements and Pesticide Residues in Medicinal Herbs Available in Pharmaceutical Market.

The use of medicinal plants for self-medication of minor health conditions has become a widespread practice in contemporary society. Few consumes, however, question the contamination of these products with toxic factors resulting from the planet's increasingly polluted environment. This paper presents the levels of five toxic elements (As, Cr, Pb, Cd, and Hg) and nine organochlorine pesticides (hexachlorobenzene (HCB), lindane, heptachor, aldrin, dieldrin, endrin, p,p'DDE, p,p'DDD, and p,p'DDT) in 14 brands of regularly consumed medicinal products in Romania. The toxic elements content was determined using energy-dispersive X-ray fluorescence (EDXRF) technique, and organochlorine pesticide residues (OPCs) were quantified using gas-chromatographic method, equipped with electron capture detector (GC-ECD). The results show that in the case of Cr, Cd, and Hg, the concentrations exceeded the limit values established by World Health Organisation (WHO) for raw herbal material. The higher level of OPCs (such as p,p'DDD, p,p'DDT, aldrin, and dieldrin) was found in the samples of Hypericum perforatum-St. John's wort, Crataegus monogyna-hawthorn, and Epilobium parviflorum-hoary willowherb. The correlations between the content of toxic elements and pesticides were determined by statistical analysis. Hierarchical clustering technique was used to detect natural grouping between the toxic elements and pesticides. For herb samples, four clusters were identified, the strongest correlated cluster consisting of Pb, HCB, Cr, and Hg. A further analysis within this cluster suggested that Cr levels are statistically different from the rest of the elements.

Bioactive Materials Based on Hydroxypropyl Methylcellulose and Silver Nanoparticles: Structural-Morphological Characterization and Antimicrobial Testing

The progress achieved in recent years in the biomedical field justifies the objective evaluation of new techniques and materials obtained by using silver in different forms as metallic silver, silver salts, and nanoparticles. Thus, the antibacterial, antiviral, antifungal, antioxidant, and anti-inflammatory activity of silver nanoparticles (AgNPs) confers to newly obtained materials characteristics that make them ideal candidates in a wide spectrum of applications. In the present study, the use of hydroxypropyl methyl cellulose (HPMC) in the new formulation, by embedding AgNPs with antibacterial activity, using poly(N-vinylpyrrolidone) (PVP) as a stabilizing agent was investigated. AgNPs were incorporated in HPMC solutions, by thermal reduction of silver ions to silver nanoparticles, using PVP as a stabilizer; a technique that ensures the efficiency and selectivity of the obtained materials. The rheological properties, morphology, in vitro antimicrobial activity, and stability/catching of Ag nanoparticles in resulting HPMC/PVP-AgNPs materials were evaluated. The obtained rheological parameters highlight the multifunctional roles of PVP, focusing on the stabilizing effect of new formulations but also the optimization of some properties of the studied materials. The silver amount was quantified using the spectroscopy techniques (energy-dispersive X-ray fluorescence (XRF), energy-dispersive X-ray spectroscopy (EDX)), while formation of the AgNPs was confirmed using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and dynamic light scattering (DLS). Also, the morphological examination (Atomic Force Microscopy (AFM) and Scanning electron microscopy (SEM)) by means of the texture roughness parameters has evidenced favorable characteristics for targeted applications. Antibacterial activity was tested against Escherichia coli and Staphylococcus aureus and was found to be substantially improved was silver was added in the studied systems.

Applications of Energy Dispersive X‐Ray Fluorescence Spectrometry and Direct Current Arc Atomic Emission Spectroscopy Methods for Grouping Study of Automobile Windshield Glasses for Glass Forensics

AbstractA comprehensive evaluation was carried out for elemental characterization of automobile glasses having potential forensic application by Energy Dispersive X‐ray Fluorescence (ED‐XRF) spectrometry and Direct Current Atomic Emission Spectroscopy (DC Arc AES). The methods were optimized and validated using geological certified reference materials and glass standard reference material. Total seventeen elements including five major elements (Si, Na, Ca, Mg and Fe) and twelve minor and trace elements (Al, Ti, V, Cr, Mn, Ni, Cu, Zn, Rb, Mo, Zr and Sr) were found to be present. Though DC Arc AES performed better for minor and trace level determination, however, the precision was evaluated as 15–20 % RSD. On the contrary, ED‐XRF performed better for major elements with 5–10 % RSD. The detection limits for the analytes prone to form refractory oxides on heating were found to be poorer in DC Arc AES compared to ED‐XRF. Statistical analyses were also performed to evaluate the reliability of the data obtained by the optimized methods. As a part of forensic applications, the elemental concentrations of minor and trace elements were utilized for the grouping study of the glass samples by cluster analysis using average linkage method.

Photochromic cellulose nanofibers-reinforced polyacrylic acid self-healable hydrogel toward dual-mode security authentication stamp

Photochromic inks have displayed various disadvantages such as poor durability, high cost and limited efficiency. The self-healing inks have shown to be more durable and photostable. In order to create an authentication stamp, UV-induced photochromic hydrogel inks with self-healable capabilities were developed. Nanoparticles of rare-earth aluminate (NREA) were synthesized and dispersed in a combination of cellulose nanofibers (CNF) and polyacrylic acid (PAA) to create an organic-inorganic hybrid ink. NREA were produced and analyzed using transmission electron microscope (TEM), revealing diameters of 1–4 nm. CNF were synthesized to act as a nanofiller and dispersing agent to improve the mechanical strength of the polyacrylic acid bulk and to prevent the agglomerates of the NREA. In order to create transparent prints, NREA must be uniformly disseminated in the CNF/PAA hybrid hydrogel ink without clumping. A paper surface was effectively stamped with the photochromic ink, and then the ink was thermofixed. Transparency was achieved by direct stamping of a consistent photochromic layer on the sheet surface, and this film was shown to become green when exposed to ultraviolet light as verified by photoluminescence spectral and CIE Lab analysis. The luminous paper sheets had an emission wavelength at 519 nm when irradiated at 368 nm. Energy-dispersive X-ray (EDX), infrared spectroscopy (FT-IR), X-ray fluorescence and scanning electron microscope (SEM) were utilized to examine the morphology of the stamped sheets. The cellulose nanofibers displayed diameters of 9–17 nm. The printed hydrogel ink displayed highly reversible photochromic emission without fatigue. Mechanical testing of the printed sheets and examination of the rheology of the luminous hydrogel was explored. The current NREA@CNF/PAA hydrogel ink offers a competent method for anticounterfeiting that can be used in a variety of authentication industries.

Preparation of fluorescent ink using perylene-encapsulated silica nanoparticles toward authentication of documents

Novel inorganic–organic hybrid fluorescent ink was produced for anticounterfeiting applications. Pigment/resin ink formulations were prepared from the thermally and photostable fluorescent perylene-doped silica nanoparticles (PSN). To create a colorless printed film from pigment/resin ink, the fluorescent perylene must be physically disseminated without clumping. Using screen-printing technique, the pigment/resin combination was successfully applied to sheets of cellulose paper. CIE Lab tests showed that pigment concentrations as low as 1 % result in a red emission when a uniform fluorescent layer was produced on the pale yellow cellulose paper surface. These printed sheets displayed an absorption band at 436 nm and an emission band at 625 nm. The fluorescent PSN exhibited diameters of 6–33 nm. The printed paper sheet was analyzed using various spectroscopic techniques, including scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), energy-dispersive X-ray (EDX), and wavelength dispersive X-ray fluorescence (WDXRF). Upon repeated exposure to UV light, the prints exhibited a reversible fluorescence. Investigations into the ink rheological characteristics, stability, and printability were conducted.

A study by portable X-ray fluorescence (pXRF) of the painting “Still Life with Vase, Plate and Flowers” (1886–1888)

Portable energy-dispersive X-ray fluorescence spectroscopy (pXRF) was employed in the characterization of the pigments present in the painting “Still Life with Vase, Plate and Flowers”, of unknown authorship, but previously attributed to Vincent van Gogh, belonging to the collection of the São Paulo Museum of Art (MASP). In situ pXRF measurements were carried out by means of a portable system in order to provide the museum with a scientific documentation about the materials in the painting. Spectra were taken at different color regions and different hues in the pictorial layer. Some of the materials identified in the painting were chalk and/or gypsum, lithopone, lead white, zinc white, bone black, barium yellow, chrome yellow, yellow ochre, chrome green, Prussian blue, cobalt blue, vermilion and red earth. Besides that, it was possible to suggest the use of a lake pigment. The pigments whose use is suggested by this work are in total agreement with those available to European artists in the end of the 19th century.

An Experimental Study on the Measurement of Gamma-Ray Linear Attenuation Coefficients with Transmission Factors for Ispir and Kızılcahamam Dry Bean

In the present work, the gamma-ray linear attenuation coefficients (µ) and transmission factors (TF) were measured for Erzurum Ispir dry bean (IDB) and Ankara Kızılcahamam dry bean (KDB). Photons of the Am-241 point source with an energy of 59.54 keV, an Energy Dispersive X-Ray Fluorescence Spectrometer (EDXRFS), and a Si (Li) detector were used in the experiment. As a result, it was observed that the average transmission factor of Erzurum İspir dried beans was higher than that of Ankara Kızılcahamam dry beans, and the average linear attenuation coefficient was smaller. This means that Ankara Kızılcahamam dry beans absorb more gamma rays than Erzurum İspir dry beans, that is, they interact more with gamma rays.

XRF Semi-Quantitative Analysis and Multivariate Statistics for the Classification of Obsidian Flows in the Mediterranean Area

Obsidian is a natural volcanic glass formed after eruptions if very rapid cooling of lava occurs. In particular conditions, the lava silicate ions cannot reach the crystalline lattice ordered formation and assume a chaotic arrangement, giving origin to obsidian flows. Obsidian has been used since the Paleolithic period to make tools because of its durability; in the Neolithic period, its trade played an important role in the Mediterranean area, and currently, obsidian is of particular interest for tracing prehistoric trading patterns. In this work, we present a semi-quantitative approach, exploiting energy-dispersive X-ray fluorescence (ED-XRF) coupled with principal component analysis. We consider geological samples from the five main collection sites of archaeological interest in the Mediterranean Basin (i.e., Pantelleria, Lipari, Palmarola, and Sardinia islands in Italy and Milos Island in Greece) and obtain a reliable classification of the fragments’ provenance, also comparing chemical fingerprints with data from the literature. Reported results show that this non-invasive semi-quantitative protocol could ease the application to archaeological samples, such as blades and splinters, permitting the classification of artifacts found in the archeological sites of the Mediterranean area even when relatively few samples are considered.