Search

Mercury long-chain carboxylates have been identified recently as degradation products resulting from saponification occurring in painted artworks. Saponification belongs among the degradation processes endangering undesirably the appearance and stability of painted artworks, significant treasures of humanity. The mechanism of saponification has not been still fully understood because of the enormous complexity of both painting materials and factors triggering the deterioration. Moreover, the properties and stability of metal soaps resulting from this degradation are also poorly understood, complicating the choice of suitable conservation treatment. Relining, a heat-based restoration technique for reinforcing deteriorated canvases, can induce irreversible changes in paint layers, being applied inappropriately. Within this study, we report thermal behavior and stability of mercury palmitate (Hg(C16)2), mercury stearate (Hg(C18)2), and their respective mixtures with linseed oil in the temperature range of 25–150 °C, employing a combination of techniques, including DSC, TG-MS, FTIR, XRPD, and in situ high-temperature FTIR and XRPD. It was observed that while Hg(C16)2 and Hg(C18)2 undergo partial decomposition around 150 °C, in a mixture with linseed oil, they decompose rapidly at significantly lower temperature (around 100 °C). The decomposition of mercury carboxylates results in the formation of metallic mercury, a volatile toxic substance, and free fatty acids, reactants capable of further development of saponification in paint layers. In addition, a structural polymorph of Hg(C16)2 and Hg(C18)2 with a different arrangement of carboxylate groups around the mercury atom was formed after the heat treatment during the cooling down at ca 120 °C as documented by in situ high-temperature XRPD and FTIR. [ABSTRACT FROM AUTHOR]

The Roman provinces did not exist as entities but as a part of a complex system involving their urban and rural landscape, communications and networks. This paper explores evidence for ceramic production within the territory of the Augustan colony of Patras, highlighting the city’s significance as a major production center due to its strategic position in regional and long-distance trading networks. Regarding the archaeological evidence, 60 sites with evidence for ceramic production were studied, providing new data on their architectural structures, workshops and kilns as well as spatial organization within Patras and its territory. The prime focus of the work, focused on the definition of local Roman wares. Hence, 150 samples were selected from the kilns and their surrounding area for typological and fabric analysis. This paper offers the first systematic archaeometric analysis of Roman ceramics from the city of Patras and serves as a major guide-line for defining what was actually produced locally (e.g. grey and red sigillatas, plain ware vessels, ceramic building materials and amphorae). Petrographic analysis enabled us to determine the local compositional patterns establishing that there are five fabrics encountered among the various workshops with few compositional differences, indicating that they derive possibly from the same locally available clay deposits. Imported (Italian) terra sigillatas could also be successfully distinguished. Mineralogical analysis through X-Ray Powder Diffraction (XRPD) allowed the study of the nature of the raw materials used and enabled the estimation of kiln firing temperatures, which ranged from 700 to 1100 °C, thereby offering vital insights into ceramic technology. [ABSTRACT FROM AUTHOR]

This study examines limestone properties and calcination process to enhance product quality. Limestone burning produces lime (CaO, calcium oxide) and carbon dioxide (CO2). Lime is a substance highly reactive and turns into slaked lime (Ca(OH)2, calcium hydroxide) when exposed to water. Six limestone samples from Tuscan Nappe sedimentary sequence, outcropping in the Monti d'Oltre Serchio area (NW Tuscany, Italy), were selected and calcined at different temperatures (800, 900, 1000 and 1100 °C). The obtained lime was slaked, and chemical, mineralogical and petrographic analyses were conducted to study its reactivity during slaking process. Key factors influencing lime reactivity were identified: calcination temperature/time and limestone characteristics (chemical and mineralogical composition). The lime reactivity was measured through the rate of lime hydration reaction. Results showed that higher reactivity in lime, lower calcination temperature. The increase in temperature and time leads to an increase of CaO grain size and, consequently, to a decrease in reactivity. Temperature increase has a more significant effect on the increasing of grain size and reactivity than time. The optimal calcination temperature was found to be 900 °C, like that of ancient limekilns. The study emphasized the close link between lime reactivity and chemistry/mineralogy of limestone. Overall, the research provides insights for improving limestone calcination processes and obtaining superior products. [ABSTRACT FROM AUTHOR]

A multi‐analytical approach based on colourimetry, micro‐Raman spectroscopy, scanning electron microscopy, optical microscopy and powder X‐ray diffraction, has been applied to investigate Roman cooking ware samples dating back to imperial age (I‐II century AD). In particular, the highly distinctive production of pots coming from two different archaeological sites, ‘Villa della Piscina’ at Centocelle district and the so called ‘Minerva Medica Temple’ at Esquilino district (Rome, Italy), was studied characterising the colour, the chemical, mineralogical and petrographic distinctive properties of the investigated samples, in order to compare technological and provenance aspects. Classification of ceramic fragment by colorimetry, integrated by compositional studies with a main contribution of micro‐Raman spectroscopy, allows to discriminate between superior and inferior quality cooking ware and evaluate the compatibility of the investigated samples with some pottery realised in known manufacturing sites in Lazio. Compositional and petrographic features allow assignment of samples from ‘Villa della Piscina’ testifying productions in the surroundings of Rome, while an importation from outsider workshops is hypothesised for the ceramic fragments from the so called ‘Minerva Medica Temple’. For these, an importation from outsider workshop is hypothesised. [ABSTRACT FROM AUTHOR]

The research focuses on analyzing the production techniques and materials of a Roman paint-plastered ceiling from a Late Antique Roman villa near Negrar (Verona, Italy), recently uncovered. Stylistic features of the decoration, found in reworked collapse debris during the villa’s excavation, date the ceiling to the original construction phase in the 4th century CE. The paper presents the protocol we adopted for recovering and analyzing the painted decoration of the villa, which was in-laboratory recomposed in its original layout after a meticulous and systematic retrieval of fragmented materials. Microsamples of mortar and pigment were then taken to fully reconstruct the execution technique and raw materials used in the paint-plastered ceiling, detailing the application of the tectorium and pigment preparation. Mortar samples were analyzed to define preparatory layer properties, using various analytical techniques including Transmitted-Light Polarized Optical Microscopy (TL-OM) and Scanning Electron Microscopy with Energy Dispersive X-Ray Analysis (SEM-EDS). Optical reflected-light microscopy detected guide incisions on the preparatory mortar, while Reflected-Light Optical Microscopy (RL-OM) revealed the microstratigraphy of pictorial micro-layers. Micro-samplings of painted decorations were conducted to define pigment palettes, determining their mineralogical composition through X-Ray Powder Diffraction (XRPD) analysis coupled with micro-Raman analyses for the determination of carbon-based compounds. The research aims to establish a comprehensive protocol for future endeavors, integrating archaeological reassembly with precise micro-analyses of pigments and mortars, deciphering the intricate layout of ancient, fragmented decorations. This study is the first of its kind in Northern Italy, overcoming challenges posed by fragmented and reworked artifacts in previous research, enabling detailed analytical studies like those conducted here. Moreover, this study of the paint-plastered ceiling of the Late Roman villa of Negrar aims to provide a new impulse for the knowledge of Late Antique painting techniques and materials, which were only marginally considered within Roman painting tradition so far. [ABSTRACT FROM AUTHOR]

In the field of historical buildings, the wide use of lime as a binder in various contexts of application emerges from a series of artistic and archaeological evidence in the Apulia (Italy) from the 4th century BCE to the 15th century CE. The large availability of carbonate rocks in the geological substratum from Daunian Subappennines to Salento areas strongly influenced the material culture of the region. In this paper, significant study cases were presented to bring to light the technological complexity, almost completely cancelled by the widespread presence of industrial products, in the use of lime over the centuries. Through examples of use from antiquity to the modern age in Apulia (Egnatia, Lamapopoli, Tertiveri, Siponto, Lucera and Monopoli sites), technological solutions indicating an ecological dimension of production were discussed, bearing witness to technologies on a human scale and sustainability. The comparison of petrographical (POM, SEM-EDS) and mineralogical (XRPD) results indicated the technological trend and custom for lime production in the Apulian region that starts from the choice of the stone to be calcined and the aggregates and passes through the modalities of lime hydration and preparation of the mixture up to the laying. [ABSTRACT FROM AUTHOR]

Have you ever looked at a powder diffractogram during a routine qualitative test and wondered how much of a particular powder compound is in the powder material? Several methods can work this out, but none of them could be used in our case because something was missing from each in performing a rapid quantity test for an active ingredient in a tablet. A semiquantitative method of an X-ray powder diffraction analysis of products containing sildenafil citrate is proposed. This method utilizes calibration curves for the most common compositions encountered in falsified and not-registered Viagra analogues. Sildenafil doses are established for singularly prepared powder probes of a medicinal product, and two runs of data collection are used: the first, the fast one, for the qualitative analysis of the product, and the second for selected 2θ regions for the API and identified excipients. An example of a product composed mainly of sildenafil citrate, gypsum and microcrystalline cellulose is discussed in detail. The data obtained from X-ray experiments were compared with the results obtained from validated liquid chromatography coupled to a diode array detector and mass spectrometry methods. [ABSTRACT FROM AUTHOR]

Understanding the mechanisms controlling the early (fresh) and long‐term (hardened) hydration of one‐part alkali‐activated slags (AAS) is key to extend their use as low CO2 substitutes for ordinary Portland cement (OPC). Their "just add water" use makes them easier and less hazardous to manipulate than the more studied two‐part ones. This is due to the absence of liquid alkaline activators, which are environmentally and energy demanding. In this work, numerous experimental techniques have been linked to obtain a comprehensive physico‐chemical characterization of a one‐part AAS activated with Na2CO3 and Ca(OH)2 powders at several water to solid ratios (w/s). Calorimetry and pH/conductivity measurements describe the functioning of the activators immediately after contact with water. Early reactivity is characterized through in situ X‐ray powder diffraction (XRPD) and small amplitude oscillatory shear (SAOS) rheology, which reveal a rapid precipitation of nanometric hydration products (nano‐C‐A‐S‐H), which results in a continuous increase in the paste cohesivity until setting. Moreover, SAOS shows that rejuvenating the paste by means of shearing (performed externally to the rheometer in this study) is enough to restore the initial cohesion (i.e., workability) for long time spans until setting occurs. The long‐term hydration is characterized by ex situ XRPD on aged AAS pastes, in parallel with mechanical testing on AAS mortar. A correlation can be observed between the amount of nano‐C‐A‐S‐H and the increase in compressive strength. Overall, this formulation shows satisfactory fresh and solid properties, demonstrating suitability for low‐ and normal‐strength applications. [ABSTRACT FROM AUTHOR]

Purpose: Pharmaceutical cocrystals are gaining attention from pharmaceutical industries and researchers because of their applicability, scalability, and cost-effectiveness. During the development process of pharmaceutical cocrystal, rigorous screening of coformer is required to select an appropriate coformer. Methods: In the present study, efavirenz (EFV) and seven coformers were screened using in silico and experimental techniques like the ∆pKa rule, Hansen solubility parameter (HSP), virtual screening, and thermal method. The predicted screening results exhibit the feasibility of the formation of four (∆pKa rule), five (HSP), and three (thermal) cocrystals within a set of experimental coformer. Results: Results exhibit the formation of three new cocrystals of EFV with nicotinamide, glutaric acid, and caffeine by using the liquid-assisted grinding method. Based on the experimental outcome, it is predicted that the ∆pKa rule and HSP are versatile techniques for screening coformer, whereas the thermal method exhibits very relevant results. The virtual screening of EFV with all coformer through CCDC GOLD software shows good intermolecular interaction and formation of hydrogen bonds. The prepared cocrystal was evaluated with differential scanning calorimetry (DSC), Fourier transmission infrared spectroscopy (FTIR), X-ray powder diffraction, solubility, and in vitro drug release studies. Conclusion: The screening techniques like HSP, ∆pKa rule, thermal method, and virtual screening were successfully implemented in the formulation of three cocrystals of an antiviral agent EFV. [ABSTRACT FROM AUTHOR]

Casamassima old town, locally known as "blue town", is widespread stratified blue paint covering the facades of the historical buildings, not reported in the archival data and historical sources. The archaeometric results presented in this study aimed to investigate raw materials, in particular pigments, used to cover the facades to contribute more precisely to the historical reconstruction of this local custom. A set of nine samples was collected from two representative historical buildings and observed by reflected light optical microscopy and scanning electron microscope (SEM-EDS) and their mineralogical characterisation was carried out by means of X-ray powder diffractometry (XRPD). The comparison of the mineralogical and elementary results and the stratigraphic, morphological, and microstructural observations made it possible to highlight a significant stratification of these plasters and to recognize the artificial ultramarine blue applied with lime, as the main mineral pigment, together with red ochre and blanc fixe. The identification of pigments was crucial to date the blue plasters. [ABSTRACT FROM AUTHOR]

Many regions of the United States contain manganese deposits economically valuable in New England, Appalachian, and Piedmont regions in the Eastern United States, in Northern Arkansas, and, to a small extent, in Central–Western California. Mn oxide/hydroxide (commonly referred to as Mn oxide minerals) are found in a wide variety of geological settings and occur as fine-grained aggregates, veins, marine and freshwater nodules and concretions, crusts, dendrites, and coatings on rock surfaces (e.g., desert varnish). How manganese oxides form and what mechanisms determine which oxides are likely to form are limited and still debated. This paper focuses on Mn oxides collected at the southern bound of the abandoned open-pit site called Crimora Mine (Augusta County, Virginia). This study uses mineralogical and chemical features to shed light on the origin of manganese deposits in Crimora along the western foot of the Blue Ridge in South–West Virginia. We report the first detailed study on the genesis of the Crimora manganese deposit conducted since the mine was closed in the 1950s. Crimora Mine sample is dark black fine- to medium-grained round and oblong nodules coated with a fine-grained intermix of yellowish earthy limonite, clays, and quartz. Scanning electron microscopy (SEM) revealed that the Crimora Mn-oxides exhibit concentric layering, breccia-like matrices, and veins. X-ray powder diffraction (XRPD) identified the set of Mn minerals as hollandite and birnessite. The concentration and range of dissolved chemical species in freshwater, seawater, and hydrothermal depositional fluids impart a geochemical signature to the Mn-oxides, providing a diagnostic tool to shed light on their genetic origin. Inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis of the Crimora manganese oxides shows Mn, Fe, and Ti, as well as trace elements such as Co, Ba, Y, Zn, Cr, Ni, Tl, La, V, and Li. A bivariate analysis based on the geochemical correlation of Mn and other common substituting cations (e.g., Fe, Co, Ti) shows a mixed genesis in different environments with varying biological and sedimentary supergene (freshwater and marine) conditions. These data suggest that the Mn-rich deposit in Crimora, VA, was formed in a continental margin environment of surficial deposits and reprecipitated in mixed biogenic and supergene conditions. [ABSTRACT FROM AUTHOR]

Pyrotechnology has always been a core topic in the archaeological debate concerning phases of deep cultural transformations, such as the Chalcolithic period in the Near East (c. 6000–3500 BC). However, previous studies on pyrotechnological installations, such as pottery kilns, pertaining to this period, have often been mainly descriptive, with a limited use of archaeometric investigations. This work presents a multi-method investigation of a Chalcolithic kiln recently discovered in the Bora Plain (part of the larger Peshdar Plain, in Iraqi Kurdistan), which combines stratigraphic analysis, pyrotechnological, micromorphological, and micro-remains analyses. Since this kiln represents the first Chalcolithic architectural feature excavated in the Bora Plain, this work offers precious insights into the pyrotechnology of the period, which is still relatively poorly understood, through the reconstruction of the kiln’s use and abandonment processes. The analytical outputs can be used to compare with other Near East kilns from the Chalcolithic and later periods.

Construction and demolition waste (CDW) from earthquake rubbles was used here as recycled aggregates (RA) in cementitious binders. The materials were sorted in six groups: concrete (CO), natural stone (NS), tile (TI), brick (BR), perforated brick (PF) and roof tile (RT). The abundance (wt.%) of crystalline phases in each RA type was determined by X-ray Powder Diffraction (XRPD). Each group of RAs was used alone (100 wt.% of RA) and mixed with quartz-rich virgin aggregates (VA) to prepare 13 types of mortars (12 specimens per type): one reference mortar (RM) with only VA, six recycled aggregate mortars (RAM) and six recycled-plus-virgin aggregate mortars (RVAM). The physical and mechanical properties of aggregates and mortars reflect the type and abundance of crystalline phases in each CDW group. Recycled mortars rich in concrete, natural stones and tiles have better mechanical performance than mortars prepared with recycled bricks, perforated bricks and roof tiles. For each RA, RVAMs have superior mechanical characteristics than the corresponding RAM. Since the type and amount of phases contained in recycled aggregates strongly control the mechanical performance of new construction materials, they should be routinely quantified as reported here, in addition to other physical features (water absorption, density, etc.). The separation of heterogeneous CDW into homogeneous RA groups is necessary for the production of new construction materials with stable and predictable performances to ensure CDW recycling, especially in areas hit by major adverse events, where large amounts of still valuable materials could be used for reconstruction processes. [ABSTRACT FROM AUTHOR]

Zirconia-based bioceramics, one of the most important materials used for dental applications, have been intensively studied in recent years due to their excellent mechanical resistance and chemical inertness in the mouth. In this work, the structural, morphological and dissolution properties of the Zr1−xMgxO2 (x = 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3) system, prepared by the conventional ceramic method, were evaluated before and after immersion in saliva substitute gel (Xerostom®, Biocosmetics Laboratories, Madrid, Spain), one of the most common topical dry mouth products used in dentistry. The X-ray powder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS) techniques were employed to investigate the phase transformations and morphology of the ceramics during the degradation process in Xerostom®. In vitro analyses showed overall good stability in the Xerostom® environment, except for the x = 0.05 composition, where significant t- to m-ZrO2 transformation occurred. In addition, the strong interconnection of the grains was maintained after immersion, which could allow a high mechanical strength of the ceramics to be obtained. [ABSTRACT FROM AUTHOR]

Introduction: Bottom ash (BA) constitutes a significant by-product obtained during the incineration of municipal solid waste in waste-to-energy (WtE) plants. BA is a heterogeneous material made of different fractions, glass, minerals, metals, and unburned residual organic matter. Due to the non-hazardous nature of the unburned material, BA can be effectively recycled, becoming a valuable resource. However, BA displays a high content of potentially toxic elements (PTEs) within its finer grain size. The presence of these elements raises concerns regarding the potential toxicity associated with BA.Materials and methods: The release of PTEs in the smaller fraction (0.063–0.2 mm; 0.3–0.5 mm; 2–4 mm; bulk

Introdução: A qualidade dos medicamentos tem sido inaceitável em muitas regiões do mundo, especificamente em países subdesenvolvidos, devido à escassez ou ausência total de laboratórios de controlo de qualidade de medicamentos (Devall, 2013). De facto, medicamentos falsificados ou de baixa qualidade constituem uma séria preocupação para a saúde pública, particularmente em países onde os sistemas de vigilância são fracos e ineficientes. Países como Índia, China, Vietname, Indonésia, Paquistão ou Filipinas têm sido identificados como os principais produtores de medicamentos falsificados; ao passo que, China (Hong Kong), Emirados Árabes Unidos, Egipto, Camarões e Turquia parecem ser os principais pontos de trânsito destes produtos farmacêuticos falsificados enviados para o resto do mundo (OCDE, 2020). Objetivo: Avaliação de vários métodos empregados para analisar a qualidade de Medicamentos. Material e Métodos: Foram coletados comprimidos com fármacos anti- inflamatórios não esteroides (AINEs) e antimaláricos, tais como, Zibufeno (Ibuprofeno 400mg), Diclomex 100 (Diclofenac sódico), Amidol® (paracetamol 500 mg), Quini PLUS®-500 (Quinino Sulfato) e Quini PLUS®-300 (Quinino Sulfato), obtidos de vendedores no mercado da Retranca, localizado no município de Cacuaco, província de Luanda, Angola e analisados por Calorimetria Diferencial de Varrimento (DSC), Espectroscopia de Infravermelho com Transformada de Fourier (FTIR) e Difração de Raios-X em Pó (XRPD) (Vueba et al., 2013). Resultados: Confirmou-se a presença da substância ativa como Zibufen e Amidol por DSC, FTIR e XRPD nos comprimidos; enquanto o Diclomex 100 não permitiu a identificação do diclofenac sódico no comprimido. Além disso, o sulfato de quinino no Quini Plus 500 mg e 300 mg só foi identificado por FTIR e XRPD. A análise das substâncias estudadas mostrou que durante a análise térmica podem ocorrer fenómenos como desidratação e (ou) fusão, e transformação cristalina. Conclusões: O estudo demonstrou a aplicação bem-sucedida dos métodos analíticos para avaliar a qualidade dos medicamentos. Os resultados desta investigação vão permitir à monitorização contínua da qualidade dos medicamentos comercializados para garantir a segurança e eficácia destes produtos no tratamento de muitas doenças em Angola.

The overall need for the preparation of new medicinal radionuclides has led to the fast development of new sorption materials, extraction agents, and separation methods. Inorganic ion exchangers, mainly hydrous oxides, are the most widely used materials for the separation of medicinal radionuclides. One of the materials that has been studied for a long time is cerium dioxide, a competitive sorption material for the broadly used titanium dioxide. In this study, cerium dioxide was prepared through calcination of ceric nitrate and fully characterized using X-ray powder diffraction (XRPD), infrared spectrometry (FT-IR), scanning and transmission electron microscopy (SEM and TEM), thermogravimetric and differential thermal analysis (TG and DTA), dynamic light scattering (DLS), and analysis of surface area. In order to estimate the sorption mechanism and capacity of the prepared material, characterization of surface functional groups was carried out using acid-base titration and mathematical modeling. Subsequently, the sorption capacity of the prepared material for germanium was measured. It can be stated that the prepared material is prone to exchange anionic species in a wider range of pH than titanium dioxide. This characteristic makes the material superior as a matrix in 68Ge/68Ga radionuclide generators, and its suitability should be further studied in batch, kinetic, and column experiments. [ABSTRACT FROM AUTHOR]

Two commercial stoneware pastes traditionally used to produce ceramic objects were evaluated. The objective was the comparative characterization of the pastes and to find the most suitable to obtain fine ceramic objects using the pottery wheel. Both ceramic pastes were characterized by X-ray powder diffraction (XRPD), particle size analyses (laser diffraction) and thermal analyses (thermogravimetry-TG, its derivative-DTG, and differential thermal analysis-DTA). The technological properties like linear drying and firing shrinkage, moisture content and plasticity were also determined. The results showed that both pastes have appropriate properties making them suitable for plastic shaping by pottery wheel. In addition, the stoneware paper clay paste is "greener" due to its content of cellulose fibers which can come even from recycled paper. [ABSTRACT FROM AUTHOR]

The goal of this work is to study the thermal behavior and the antibacterial properties of a MgAl-CO3 layered double hydroxide (LDH), which demonstrated high efficiency in removing chromium (VI) from contaminated industrial wastewater. The compound has been synthesized via co-precipitation route (direct method) followed by hydrothermal treatment, obtaining nanoscopic crystallites with a partially disordered (turbostratic) structure. After its synthesis, the compound was characterized by means of X-ray powder diffraction, field emission scanning electron microscope, inductively coupled plasma atomic emission spectroscopy and analysis and Fourier transform infrared spectroscopy. On the other hand, with the view to check the drug delivery and surgical tools usage of MgAl-CO3, antibacterial tests, performed according to the Kirby–Bauer method, revealed the inability the growth of the pathogenic bacterial strains. Thermogravimetry and differential thermal analysis revealed that evolution of water from the material occurs in two stages upon heating and a noticeable interaction takes place between water (in the vapor phase) and MgAl-CO3. Kinetic analysis of both steps provides almost constant values of activation energy, with the following average values in the range 0.1 < a < 0.9: E1 = (66 ± 9) kJ mol‒1; E2 = (106 ± 7) kJ mol‒1. Finally, prediction of reasonable reaction times extrapolated at 25 and 37 °C has been made from kinetic parameters of the first step, while almost unrealistic reaction time values were determined using the same procedure with kinetic parameters related to the second step. [ABSTRACT FROM AUTHOR]

The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer formation upon air exposure. Our findings present the fundamental work on the prototype arsenopyrite structure and have further implications for studies on ion incorporation into FeAsS structure and its environmental stability and oxidation mechanisms as a source of anthropogenic As release into the environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Crystal structure determination/confirmation of MABiI and FABiI. • Characterization of phase transitions (PT) in MABiI and FABiI by IR and DSC. • Resolving of the unambiguity related to the PT in MABiI. • Determination of the temperature-induced isosbestic points and redefinition of the phases according to IUCr. Understanding of the structural properties of hybrid organic–inorganic perovskites (HOIPs) and their behavior is crucial for their use as photovoltaics and for the design and assembly of solar cells. As part of this work, a detailed study was conducted to further understand bismuth iodide perovskites, with a specific focus on the phase transitions of methylammonium and formamidinium analogs. A detailed analysis of the temperature-dependent IR spectra was also performed in order to analyze the structural changes that occur. The presence of five phases in the methylammonium bismuth iodide (MABiI) and four phases in formamidinium bismuth iodide (FABiI) were determined. An additional confirmation of the reported results was obtained from the differential scanning calorimetry. The ambiguities concerning the crystal structure of FABiI were resolved based on the results by X-ray powder diffraction (XRPD). [ABSTRACT FROM AUTHOR]

Have you ever looked at a powder diffractogram during a routine qualitative test and wondered how much of a particular powder compound is in the powder material? Several methods can work this out, but none of them could be used in our case because something was missing from each in performing a rapid quantity test for an active ingredient in a tablet. A semiquantitative method of an X-ray powder diffraction analysis of products containing sildenafil citrate is proposed. This method utilizes calibration curves for the most common compositions encountered in falsified and not-registered Viagra analogues. Sildenafil doses are established for singularly prepared powder probes of a medicinal product, and two runs of data collection are used: the first, the fast one, for the qualitative analysis of the product, and the second for selected 2θ regions for the API and identified excipients. An example of a product composed mainly of sildenafil citrate, gypsum and microcrystalline cellulose is discussed in detail. The data obtained from X-ray experiments were compared with the results obtained from validated liquid chromatography coupled to a diode array detector and mass spectrometry methods.

Many regions of the United States contain manganese deposits economically valuable in New England, Appalachian, and Piedmont regions in the Eastern United States, in Northern Arkansas, and, to a small extent, in Central–Western California. Mn oxide/hydroxide (commonly referred to as Mn oxide minerals) are found in a wide variety of geological settings and occur as fine-grained aggregates, veins, marine and freshwater nodules and concretions, crusts, dendrites, and coatings on rock surfaces (e.g., desert varnish). How manganese oxides form and what mechanisms determine which oxides are likely to form are limited and still debated. This paper focuses on Mn oxides collected at the southern bound of the abandoned open-pit site called Crimora Mine (Augusta County, Virginia). This study uses mineralogical and chemical features to shed light on the origin of manganese deposits in Crimora along the western foot of the Blue Ridge in South–West Virginia. We report the first detailed study on the genesis of the Crimora manganese deposit conducted since the mine was closed in the 1950s. Crimora Mine sample is dark black fine- to medium-grained round and oblong nodules coated with a fine-grained intermix of yellowish earthy limonite, clays, and quartz. Scanning electron microscopy (SEM) revealed that the Crimora Mn-oxides exhibit concentric layering, breccia-like matrices, and veins. X-ray powder diffraction (XRPD) identified the set of Mn minerals as hollandite and birnessite. The concentration and range of dissolved chemical species in freshwater, seawater, and hydrothermal depositional fluids impart a geochemical signature to the Mn-oxides, providing a diagnostic tool to shed light on their genetic origin. Inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis of the Crimora manganese oxides shows Mn, Fe, and Ti, as well as trace elements such as Co, Ba, Y, Zn, Cr, Ni, Tl, La, V, and Li. A bivariate analysis based on the geochemical correlation of Mn and other common substituting cations (e.g., Fe, Co, Ti) shows a mixed genesis in different environments with varying biological and sedimentary supergene (freshwater and marine) conditions. These data suggest that the Mn-rich deposit in Crimora, VA, was formed in a continental margin environment of surficial deposits and reprecipitated in mixed biogenic and supergene conditions.

Featured Application: The paper's results could be useful in the field of sodium-ion batteries. Na0.67MnO2 (NMO) stands out among the layered cathode materials used for sodium batteries due to its high-capacity values, low cost, and environmental friendliness. Unfortunately, many drawbacks arise during cycling, but nanostructure tailoring and doping can help to mitigate them. Our aim was to synthesize undoped and Cu- or Fe-doped NMO samples via the sol-gel route, with a different cooling step to room temperature, i.e., in a natural way or via quenching. The formation of a mixture of polymorphs was observed, as well as differences in the external morphology of the powders' grains. The use of spectroscopic techniques, Mössbauer spectroscopy for the Fe-doped samples and Electron paramagnetic resonance, allowed us to gain insights into the oxidation states of transition metals and to make suggestions about the magnetic ordering, as well as on the possible presence of magnetic impurities. Cyclic voltammetry and galvanostatic cycling results were interpreted on the basis of the spectroscopic data: the introduction of substituents, in general, worsens the capacity values, due to the decrease in the P2 amount and the introduction of structural distortions. The structural stability of the samples in air as a function of time was also analyzed via X-ray diffraction, demonstrating the positive effect of Cu presence. [ABSTRACT FROM AUTHOR]

Three new bioactive nanosized supramolecular cobalt coordination polymers; {[Co2(tyr)2(Morph)2(Cl)2(H2O)2]}n (1), {[Co(Morph)6]+2[Co(bdc)(Morph)2(Cl)2]−2.3H2O}n (2) and {[Co(Morph)6]+2[Co(H2btec)(Morph)3(H2O)]−2.10H2O}n (3), where L-tyr = L-tyrosine, H2bdc = Terephthalic acid, H4btec = Pyromellitic acid and Morph = Morphline, they were prepared and characterized by elemental analysis, FT-IR and UV–VIS spectroscopies, magnetic, molar conductance, TGA/DTA, XRPD, catalytst and MM2 theoretical calculations. In all three compounds, the Morph ligand adopts a bidentate chelating coordination mode and the carboxylate anions of bdc−2 and H2btec−2 act as monodentate ligands while the tyr−1 anion act as bidentate ligand. The coordination geometry of the cobalt centers is an octahedral. The variation of carboxylates, morphline and central cobalt ions exerts a significant effect on the structures, properties and biological activity. Kinetic and thermodynamic parameters (n, E*, Z, ΔH*, ΔS* and ΔG*) were computed using Coats–Redfern equations and discussed, which confirms the second order kinetics. From the XRPD patterns, the crystal parameters as well as the particle sizes of the complexes could be evaluated. Complexes exhibit catalytic activity. The biological activity of the compounds has also been study against different bacteria and fungi. [ABSTRACT FROM AUTHOR]

Simple Summary: "Infernaccio" gorges are one of the Earth's hidden habitats in Central Italy. Beyond the deep incisions and high slopes, these gorges are characterized by black deposits in gorge walls and covering rock surfaces. Several geological events have shaped these unique geological formations and their microbiota. This study investigated microbial contribution to black deposit formation and isolating Mn-oxide-solubilizing bacteria. Our results provided evidence of the putative role of Bacteria and Archaea in forming manganese oxide deposits. Findings also showed that these deposits are a source of valuable strains with manganese oxide bioleaching properties, essential for bioremediation and metal recovery. The present study explored the microbial diversity of black deposits found in the "Infernaccio" gorge. X-ray Powdered Diffraction (XRPD) was used to investigate the crystallinity of the samples and to identify the minerals. Scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM-EDS) were used to detect the bacterial imprints, analyze microbe–mineral interactions, and highlight the chemical element distribution in the black deposits. 16S rRNA gene metabarcoding allowed the study of Archaea and Bacteria communities. Mn-oxide-solubilizing isolates were also obtained and characterized by culturable and molecular approaches. The multidisciplinary approach showed the occurrence of deposits composed of birnessite, diopside, halloysite, and leucite. Numerous bacterial imprints confirmed the role of microorganisms in forming these deposits. The Bacteria and Archaea communities associated with these deposits and runoff waters are dynamic and shaped by seasonal changes. The uncultured and unknown taxa are the most common and abundant. These amplicon sequence variants (ASVs) were mainly assigned to Proteobacteria and Bacteroidetes phyla. Six isolates showed interesting Mn solubilization abilities under microaerophilic conditions. Molecular characterization associated isolates to Brevibacterium, Bacillus, Neobacillus, and Rhodococcus genera. The findings enriched our knowledge of geomicrobiological aspects of one of the Earth's hidden habitats. The study also unveiled the potential of this environment as an isolation source of biotechnologically relevant bacteria. [ABSTRACT FROM AUTHOR]

The rework of daily refuse, including large quantities of faunal remains, is a common explanation for earthen mound construction in the Uruguayan lowlands, which started about 5000 years ago. While some earthen mounds contain human and animal bones in high abundance, several others contain only a few fragments. Thousands of years later (17th to 18th centuries), stone structures known as cairns were used in the same region and are believed to have served as the burial ground for local chiefs. However, no bone remains were ever found during excavations. The acidity of local soils has been the common explanation for the low frequency and/or complete absence of bone remains in earthen mounds and cairns. To investigate the absence of bones possibly induced by a corrosive environment, we applied Fourier transform infrared spectroscopy (FTIR), X‐ray powder diffraction (XRPD), and micromorphology to study the sediments at three sites: (1) an earthen mound rich in macroscopic bone fragments (CH2D01 site—CH); (2) an earthen mound with only a few macroscopic bone fragments (Las Palmas—LP); and (3) sediments from beneath a cairn with no macroscopic bone remains (Mario Chafalote cairn—MC). FTIR and XRPD showed the existence of burnt bones at the CH mound and a complete absence of bone mineral at LP and MC. Micromorphology revealed that, though invisible in the FTIR spectra, the LP mound contains micro‐bone fragments, but in extremely low frequency. Analyses indicate that taphonomy did not play a major role in the low frequency or absence of bones at the LP and MC sites, located in a similar environmental context, and that differences in site use and mound technology explain the contrasting composition of the CH mound. [ABSTRACT FROM AUTHOR]

Solvent-free preparation types for cyclodextrin complexation, such as co-grinding, are technologies desired by the industry. However, in-depth analytical evaluation of the process and detailed characterization of intermediate states of the complexes are still lacking in areas. In our work, we aimed to apply the co-grinding technology and characterize the process. Fenofibrate was used as a model drug and dimethyl-β-cyclodextrin as a complexation excipient. The physical mixture of the two substances was ground for 60 min; meanwhile, samples were taken. A solvent product of the same composition was also prepared. The intermediate samples and the final products were characterized with instrumental analytical tools. The XRPD measurements showed a decrease in the crystallinity of the drug and the DSC results showed the appearance of a new crystal form. Correlation analysis of FTIR spectra suggests a three-step complexation process. In vitro dissolution studies were performed to compare the dissolution properties of the pure drug to the products. Using a solvent-free production method, we succeeded in producing a two-component system with superior solubility properties compared to both the active ingredient and the product prepared by the solvent method. The intermolecular description of complexation was achieved with a detailed analysis of FTIR spectra. [ABSTRACT FROM AUTHOR]

A Messinian and lithified horizon enriched in volcanic particles with thicknesses of 170–180 cm crops in the Camporotondo (CR) section (Marche, Italy). This volcanic-rich layer (VRL) was investigated by field plus mesoscopic observations, X-ray powder diffraction (XRPD), scanning electron microscopy (SEM), bulk composition methods and electron-microprobe analysis (EMPA). The quantitative textural features of volcanic and sedimentary components were determined by 2D image analysis. The lowermost massive 70–80 cm portion is free of sedimentary structure or characterised only by plane-parallel ones, whereas the uppermost one is undulated and cross-laminated. The XRPD and SEM outcomes unveil that the VRL of CR is mainly composed of glassy shards (≥80 area%), a variable amount of sedimentary minerals (<20 area%) and a very low content of magmatic minerals (few area%). The bulk and micro-chemical attributes of volcanic and glassy materials are rhyolitic and almost identical to previous VRLs dated at 5.5 Ma (VRL-5.5). The signatures of immobile elements and the high amount of H2O present in the glass fraction suggest a provenance from a convergent geodynamic setting. The 2D image analysis on SEM observations show that the VRL-5.5 of CR is composed of very fine and sorted (averages of MZ of 5,72 and σi of 0,70), scarcely vesicular, glass shards, with similar long and short size dimensions, shape and roundness. The VRL-5.5 of CR is free of large minerals and fossils. The coupling of mesoscopic and microscopic determinations indicates that the lowermost interval was deposited such as a primary tephra, i.e., fallout pyroclasts sinking in seawater. Instead, the uppermost interval derives from local, low-energy and sin-depositional remobilisation of the same VRL-5.5. The textural attributes of the volcanic fractions, the sedimentological features and the thickness of the VRL at CR correspond to the westward deposit of a still unknown eruption likely occurred at 5.5 Ma. [ABSTRACT FROM AUTHOR]

This paper described a baseline for a multidisciplinary approach to the mineralogical and chemical characterization of eighteen fragments of archaic transport amphoras (7th-6th centuries BC) found at Gravisca archaeological site (Lazio, Italy) attributed to an Eastern Aegean provenance (six from Samos, three from Miletus, three from Chios and three from Klazomenai). The samples have been typed on the evidence concerning archaic manufactory techniques by using X-ray powder diffraction (XRPD) associated with quantitative phase analysis (QPA), optical (OM) and electron microscopy (SEM). Following Inductive Coupled Plasma Spectroscopy (ICP), compositional data analysis has been for the first time applied to selected geochemical proxies combining rare earth elements and selected heavy metals concentration in Hierarchical Agglomerative Cluster (HAC). This innovative approach allows to distinguish different sources of the raw materials used from different geological and geographical areas. Multivariate statistical treatments via Principal Component Analyses (PCA) open the possibility to group the sherds into clusters, comparing the results with the HAC application allowing to validate the methodology. Two distinct centres associated with Samos manufactory appear to be operating during 7th-6th centuries BC, which could be related to different production periods or even different production areas. The new data concur with a more straightforward historical reconstruction of archaic Poleis manufactory and commercial activity toward Etruria and the Mediterranean and with a new methodological approach to archaeometry. [ABSTRACT FROM AUTHOR]

Although solid‐state nuclear magnetic resonance (NMR) is a versatile analytical tool to study polymorphs and phase transitions of pharmaceutical molecules and products, this work summarizes examples of spontaneous and unexpected (and unwanted) structural rearrangements and phase transitions (amorphous‐to‐crystalline and crystalline‐to‐crystalline) under magic angle spinning (MAS) conditions, some of them clearly being due to the pressure experienced by the samples. It is widely known that such changes can often be detected by X‐ray powder diffraction (XRPD); here, the capability of solid‐state NMR experiments with a special focus on 1H‐13C frequency‐switched Lee–Goldburg heteronuclear correlation (FSLG HETCOR)/MAS NMR experiments to detect even subtle changes on a molecular level not observable by conventional 1D NMR experiments or XRPD is presented. Furthermore, it is shown that a polymorphic impurity combined with MAS can induce a crystalline‐to‐crystalline phase transition. This showcases that solid‐state NMR is not always noninvasive and such changes upon MAS should be considered in particular when compounds are studied over longer time spans. [ABSTRACT FROM AUTHOR]

In the pharmaceutical market, the need to find effective systems for the efficient release of poorly bioavailable drugs is a forefront topic. The inorganic–organic hybrid materials have been recognized as one of the most promising systems. In this paper, we developed new Hydroxypapatite@Furosemide hybrids with improved dissolution rates in different media with respect to the drug alone. The hybrids formation was demonstrated by SEM/EDS measurements (showing homogeneous distribution of the elements) and FT-IR spectroscopy. The drug was adsorbed onto hydroxyapatite surfaces in amorphous form, as demonstrated by XRPD and its thermal stability was improved due to the absence, in the hybrids, of melting and decomposition peaks typical of the drug. The Sr substitution on Ca sites in hydroxyapatite allows increasing the surface area and pore volume, foreseeing a high capacity of drug loading. The dissolution tests of the hybrid compounds show dissolution rates much faster than the drug alone in different fluids, and also their solubility and wetting ability is improved in comparison to furosemide alone. [ABSTRACT FROM AUTHOR]

Molecular complexation with cyclodextrins (CDs) has long been a known process for modifying the physicochemical properties of problematic active pharmaceutical ingredients with poor water solubility. In current times, the focus has been on the solvent-free co-grinding process, which is an industrially feasible process qualifying as a green technology. In this study, terbinafine hydrochloride (TER), a low solubility antifungal drug was used as a model drug. This study aimed to prepare co-ground products and follow through the preparation process of the co-grinding method in the case of TER and two amorphous CD derivatives: (2-hydroxypropyl)-β-cyclodextrin (HPBCD); heptakis-(2,6-di-O-methyl)-β-cyclodextrin (DIMEB). For this evaluation, the following analytical tools and methods were used: phase solubility studies, differential scanning calorimetry (DSC), X-ray powder diffractometry (XRPD), hot-stage X-ray powder diffractometry (HOT-XRPD), Fourier-transform infrared (FT-IR), Raman spectroscopy, and Scanning Electron Microscopy (SEM). Furthermore, in vitro characterization (dissolution and diffusion studies) was performed in two kinds of dissolution medium without enzymes. In the XRPD and SEM studies, it was found that the co-grinding of the components resulted in amorphous products. FT-IR and Raman spectroscopies confirmed the formation of an inclusion complex through the unsaturated aliphatic chain of TER and CDs. In vitro characterization suggested better dissolution properties for both CDs and decreased diffusion at higher pH levels in the case of HPBCD. [ABSTRACT FROM AUTHOR]

A size–strain line‐broadening analysis of the XRPD patterns and Raman spectra for two anatase/brookite (TiO2)‐based nanocomposites with carbon (C) was carried out and the results compared with those of a similar sample free of carbon. The crystal structures and microstructures of anatase and brookite, as well as their relative abundance ratio, have been refined from XRPD data by the Rietveld method (the low amount of carbon is neglected). The XRPD size–strain analysis resulted in reliable structure and microstructure results for both anatase and brookite. The experimental Raman spectra of all the samples in the region 100–200 cm−1 are dominated by a strong feature primarily composed of the most intense modes of anatase (Eg) and brookite (A1g). The anatase crystallite sizes of 14–17 nm, estimated by XRPD, suggest the application of the phonon confinement model (PCM) for the analysis of the anatase Eg mode, whereas the relatively large brookite crystallite size (27–29 nm) does not imply the use of the PCM for the brookite A1g mode. Superposition of the anatase Eg mode profile, calculated by the PCM, and the Lorentzian shape of the brookite A1g mode provide an appropriate simulation of the change in the dominant Raman feature in the spectra of TiO2‐based nanocomposites with carbon. Raman spectra measured in the high‐frequency range (1000–2000 cm−1) provide information on carbon in the investigated nanocomposite materials. The results from field‐emission scanning electron microscope (SEM), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR) spectroscopy and nitrogen physisorption measurements support the XRPD and Raman results. [ABSTRACT FROM AUTHOR]

Doxycycline hyclate is Biopharmaceutical Classification System, class I drug (high solubility and high permeability), but it is associated with poor photostability. It is in the class of tetracycline antibiotic, which is used to treat various infections, but its bioavailability is compromised due to its sensitivity to light and aqueous instability. In this paper, the influence of inclusion complexation with different cyclodextrins, i.e., αCD, γCD, HPβCD and RMβCD, on the photostability of doxycycline hyclate in aqueous media was investigated. Host–guest inclusion complexes were prepared by freeze- drying method. The prepared complexes were characterized for drug content, SEM, XRPD, in vitro permeation studies and photostability studies. XRPD showed diffused peaks for most of the complexes, while SEM showed irregularly shaped particles. The formulation D20 (Drug: γCD in 1:20 molar ratio) showed the highest % drug content (83.72 ± 1.2%), and the formulations D1 (Drug: αCD in 1: 2 molar ratio) showed the lowest % drug content among all the CD complexes. It was found that the photodegradation of the drug was reduced significantly upon complexation. For Drug: CD complexes, the photostability of the aqueous solution of drug/CD complexes was found to be in the order of γCD > RMβCD > HPβCD > αCD with maximum photostability shown by Drug: γCD (1:20 molar ratio) complex. The obtained results suggested that cyclodextrin complexation can be used as an alternative approach for increasing the photostability of doxycycline hyclate. [ABSTRACT FROM AUTHOR]

• Petrography of Construction and Demolition Wastes (CDWs) • Characterization of CDWs through XRPD and XRF analysis methodologies. • Proposal general protocol to analyse the petrography of CDW worldwide. The density, colour and texture, plus mineral and chemical features of 18 ceramic-like CDW samples from the Abruzzo region (Central Italy) were characterised. The concretes, natural stones, tiles, roof-tiles, bricks and perforated bricks are either aphanitic to porphyric. Concretes and natural stones are grey to white and tend to be > 2.0 g/cm3; the masonries are brown to reddish and close to < 2.0 g/cm3. Concrete and natural stone are rich or even exclusively made up of calcite, with high amounts of CaO (>40 wt%) and LOI (volatiles, CO 2 + H 2 O). The masonries are instead calcite-, CaO- (<25 wt%) and LOI-poor (<8 wt%) but enriched in SiO 2 (45 to 70 wt%) stabilised as quartz and/or cristobalite, with significant amount of Al 2 O 3 (12 to 20 wt%). S and Cl contents are similar among concrete, bricks and perforated bricks. The petrography of CDW concretes is similar among geographical areas with abundance of limestones used as aggregates. However, in limestone-poor areas CDW are SiO 2 - and Al 2 O 3 -rich, reflecting the prevalent use of masonry and/or silicate-rich construction materials, implying that each geographical area is characterised by peculiar CDW composition. Therefore, the knowledge of mesoscopic, physical and petrographic aspects has to be known for planning adequate sorting methods, promoting upcycling reusing applications. Some of the studied CDW samples are susceptible to release relative high Cr and As content. [ABSTRACT FROM AUTHOR]

Pliny the Elder testifies that roman workshops used volcanic glass (obsidian), but also produced and used a dark glass (obsidian-like glass) quite similar to the natural one. In the context of the study on medieval mosaics, the use of the obsidian and obsidian-like tesserae is a challenging research topic. In this paper, we present the results of a multidisciplinary study carried out on the Dedication wall mosaic, realized by a byzantine workshop in the 12th century in the Church of St. Mary of the Admiral in Palermo, and where numerous black-appearing tesserae, supposed to be composed of obsidian by naked-eyes observation, are present. Historical documents, multispectral imaging of the wall mosaic, and some analytical methods (SEM-EDS and XRPD) applied to a sample of black tesserae, concur in identifying here the presence of obsidian and different obsidian-like glass tesserae. This evidence, although related to the apparent tampering and restoration, could open a new scenario in the use of obsidian and obsidian-like glass tesserae during the Byzantine period in Sicily and in the reconstruction of multiple restoration phases carried out between 12th and 20th century AD on the mosaics of St. Mary of the Admiral.

Medieval glazed ceramics, dated to the early 15th century, excavated at the Belgrade Fortress, Serbia, were investigated by combining optical microscopy, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), micro-Raman spectroscopy and multivariate statistical analysis. The decoration and style of the investigated ceramics were characteristic of workshops from different areas of the medieval Serbian State: Ras, Kruševac and Belgrade/Smederevo. Comparison was made with ceramic samples from the same period excavated at the Studenica Monastery, the hitherto earliest workshop discovered, which were used as reference material for the Ras area. Ceramics from the Belgrade Fortress were covered with a transparent, lead-based glaze. The majority of the glazes were produced by application of mixture of lead oxide and quartz to the clay body, whereas only two samples were glazed by application of lead oxide by itself. The brown colours of the glaze originated from Fe-based spinel, whereas copper and iron were responsible for the colouring of the green and yellow glazes. The obtained results revealed glazing technology taken from Byzantine tradition.

Sphene based glass-ceramics (CaTiSiO5), an excellent candidate for a host lattice of ceramic materials and for nuclear waste immobilization, has been prepared from a powder mixture of CaCO3, TiO2 and SiO2 using vibro-milling for homogenization. Starting powders were melted at 1400°C for 2 h, cooled to room temperature, grounded again, then crystallized by thermal treatment yielding a sphene glass-ceramic. The evolution of the phase composition during thermal treatment was investigated by X-ray powder diffraction (XRPD), FT-IR, Raman and thermal analyses (TG-DTA). Pure synthetic single phase sphene was formed at 800°C for 4 h, even it is very hard to obtain monophase powder at such low temperature. Powder morphology was analyzed by scanning electron microscopy (SEM). [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 45012]

The behaviour and stability of arsenopyrite largely depend on its crystal structure, but studies of crystallography and structural defects are scarce. For clarification, we investigated a series of natural arsenopyrite crystals from the polymetallic Pb-Zn-(±Cu,Ag,Au,Sb,Bi,W) Šumadija-Kopaonik ore district (Serbia) by powder X-ray diffraction (XRPD). Among them, samples from the Drenjak gold mineralisation showed near-stoichiometric FeAsS composition and were further investigated by conventional and high-resolution transmission electron microscopy methods. TEM revealed abundant planar crystallographic defects and epitaxial surface oxide layer formation upon air exposure. Our findings present the fundamental work on the prototype arsenopyrite structure and have further implications for studies on ion incorporation into FeAsS structure and its environmental stability and oxidation mechanisms as a source of anthropogenic As release into the environment.

Fixed-dose combinations have shown to be a great alternative to traditional polytherapy; however, development of such formulation requires thorough physicochemical compatibility investigation of active pharmaceutical ingredients to provide a stable, safe and therapeutically effective product. In this work, differential scanning calorimetry, X-ray powder diffraction, isothermal stress testing followed by Fouriertransform infrared spectroscopy and chromatographic analysis as well as dissolution studies were used for physicochemical compatibility investigation of folic acid and balsalazide or olsalazine. Balsalazide and olsalazine as well as their blend were successfully characterised regarding their physicochemical properties using the mentioned techniques. Differential scanning calorimetry gave ambiguous results due to premature degradation of balsalazide. On the contrary, other techniques have implied the absence of any chemical reactions or physical changes in prepared blends. Obtained result imply that folic acid is compatible with both balsalazide and olsalazine which goes in favour of developing proposed fixed-dose combinations. [ABSTRACT FROM AUTHOR]

Several glass mosaic tesserae were found during the archeological excavations at the Villa di Teodorico in Galeata (Forlì‐Cesena, Emilia Romagna, Italy), dated to early sixth century AD. This work reports the results of an archeometrical investigation realized through a multi‐technique approach on 16 tesserae. The aims of the study were the determination of the glass composition, the characterization of coloring and opacifying agents, and the definition of the technological processes involved. The glass matrix and the dispersed crystallites were characterized in detail through micro‐Raman spectroscopy, field emission scanning electron microscopy with energy‐dispersive X‐ray spectroscopy, and X‐ray powder diffraction analyses. Micro‐Raman spectroscopy was proven to be very effective in the analysis of complex objects, providing information on the structure and composition of the glass and on the nature of the opacifying agents and the crystalline colorants. UV–visible–NIR diffuse reflectance spectrophotometry with optic fibers was helpful to identify the metal ions used as chromophores. The different hues were obtained by means of dispersed ions as well as crystalline compounds and metal nanoparticles. A large variety of opacifying agents was detected. Results were compared with data of contemporary mosaics within the same geographical area. [ABSTRACT FROM AUTHOR]

• Strategy for the screening analysis of falsified samples was developed. • ATR proved to be appropriate technique for PDE-5i identification in complex matrix. • Complementarity between ATR-FTIR and XRPD was demonstrated. • Developed strategy was successfully introduced into routine analysis. Falsified drugs are a growing problem and a great threat all over the world. Searching for easy, fast, not expensive and reproducible methods for identification of active pharmaceutical ingredients (APIs) is an important issue. The application of ATR-IR technique for identification of phosphodiesterase-5 inhibitors (PDE-5i) in falsified products from the Polish market has been demonstrated. Furthermore, the strategy of confirmation of the product's originality in a quick and easy way has been developed. The advantages of this application are: exceptional simplicity, very short measurement time, high selectivity in relation to structurally similar substances and almost no sample preparation. After validation, developed strategy has been successfully introduced into routine analysis. [ABSTRACT FROM AUTHOR]

The contribution that materials science has made to the understanding of ancient glassmaking is unquestionable, as research undertaken in recent decades has extensively demonstrated. Archaeological glass is far from being a homogeneous class of materials, encompassing objects made for different uses, manufactured in different periods and geographic areas, with a variety of tools and working techniques. If all these factors are not adequately considered when approaching the study of ancient glasses from an archaeometric perspective, data obtained by analyses can incur the risk of being less informative or even misinterpreted. Moving from previously performed research, this paper is aimed at reflecting on the potential of synergistic approaches for the study of archeological glasses, based on the interrelation among different disciplines and fostering the integration of archaeological and historical knowledge with data-driven scientific analyses. [ABSTRACT FROM AUTHOR]

By running a temperature series of molecular dynamics (MD) simulations starting from the known low-temperature phase, the experimentally observed phase transition in a `jumping crystal' was captured, thereby providing a prediction of the unknown crystal structure of the high-temperature phase and clarifying the phase-transition mechanism. The phase transition is accompanied by a discontinuity in two of the unit-cell parameters. The structure of the high-temperature phase is very similar to that of the low-temperature phase. The anisotropic displacement parameters calculated from the MD simulations readily identified libration as the driving force behind the phase transition. Both the predicted crystal structure and the phase-transition mechanism were verified experimentally using TLS (translation, libration, screw) refinement against X-ray powder diffraction data.

Na0.67MnO2 (NMO) stands out among the layered cathode materials used for sodium batteries due to its high-capacity values, low cost, and environmental friendliness. Unfortunately, many drawbacks arise during cycling, but nanostructure tailoring and doping can help to mitigate them. Our aim was to synthesize undoped and Cu- or Fe-doped NMO samples via the sol-gel route, with a different cooling step to room temperature, i.e., in a natural way or via quenching. The formation of a mixture of polymorphs was observed, as well as differences in the external morphology of the powders’ grains. The use of spectroscopic techniques, Mössbauer spectroscopy for the Fe-doped samples and Electron paramagnetic resonance, allowed us to gain insights into the oxidation states of transition metals and to make suggestions about the magnetic ordering, as well as on the possible presence of magnetic impurities. Cyclic voltammetry and galvanostatic cycling results were interpreted on the basis of the spectroscopic data: the introduction of substituents, in general, worsens the capacity values, due to the decrease in the P2 amount and the introduction of structural distortions. The structural stability of the samples in air as a function of time was also analyzed via X-ray diffraction, demonstrating the positive effect of Cu presence.

The present study explored the microbial diversity of black deposits found in the “Infernaccio” gorge. X-ray Powdered Diffraction (XRPD) was used to investigate the crystallinity of the samples and to identify the minerals. Scanning electron microscope and energy-dispersive X-ray spectroscopy (SEM-EDS) were used to detect the bacterial imprints, analyze microbe–mineral interactions, and highlight the chemical element distribution in the black deposits. 16S rRNA gene metabarcoding allowed the study of Archaea and Bacteria communities. Mn-oxide-solubilizing isolates were also obtained and characterized by culturable and molecular approaches. The multidisciplinary approach showed the occurrence of deposits composed of birnessite, diopside, halloysite, and leucite. Numerous bacterial imprints confirmed the role of microorganisms in forming these deposits. The Bacteria and Archaea communities associated with these deposits and runoff waters are dynamic and shaped by seasonal changes. The uncultured and unknown taxa are the most common and abundant. These amplicon sequence variants (ASVs) were mainly assigned to Proteobacteria and Bacteroidetes phyla. Six isolates showed interesting Mn solubilization abilities under microaerophilic conditions. Molecular characterization associated isolates to Brevibacterium, Bacillus, Neobacillus, and Rhodococcus genera. The findings enriched our knowledge of geomicrobiological aspects of one of the Earth’s hidden habitats. The study also unveiled the potential of this environment as an isolation source of biotechnologically relevant bacteria.