In a broad project designed to examine uranium transport by surface water from Sierra Peña Blanca to Laguna del Cuervo in the Chihuahuan Desert, sediments from intermittent streams and the lagoon have been extracted and studied. Two samples were sediments from the high area of the Sierra, close to the uranium deposit “El Nopal.” Moreover, 23 core segments extracted for dating sediments were analyzed to consider changes in the fine component concentrations. The techniques of scanning electron microscopy–energy dispersive X-ray spectroscopy, XRD in a conventional diffractometer, and high-resolution synchrotron XRD analysis were applied. The crystallographic objective of the present work was to evaluate the functionality of various methodologies when applied to cases of a detailed analysis of many polyphase samples with cryptocrystals. The methods for processing the experimental data were the Rietveld method in the current multi-pattern variant of the Fullprof program and the degree of crystallinity method for the rapid estimation of the proportion of cryptocrystals in a mixture. This last technique was developed with an ad hoc software package deposited in the GitLab public repository.

A functional food as a matrix based on a blend of carbohydrate polymers (25% maltodextrin and 75% inulin) with quercetin and Bacillus claussi to supply antioxidant and probiotic properties was prepared by spray drying. The powders were characterized physiochemically, including by moisture adsorption isotherms, X-ray diffraction (XRD), scanning electron microscopy (SEM), and modulated differential scanning calorimetry (MDSC). The type III adsorption isotherm developed at 35 °C presented a monolayer content of 2.79 g of water for every 100 g of dry sample. The microstructure determined by XRD presented three regions identified as amorphous, semicrystalline, and crystalline-rubbery states. SEM micrographs showed variations in the morphology according to the microstructural regions as (i) spherical particles with smooth surfaces, (ii) a mixture of spherical particles and irregular particles with heterogeneous surfaces, and (iii) agglomerated irregular-shape particles. The blend’s functional performance demonstrated antioxidant activities of approximately 50% of DPPH scavenging capacity and viability values of 6.5 Log10 CFU/g. These results demonstrated that the blend displayed functional food behavior over the complete interval of water activities. The equilibrium state diagram was significant for identifying the storage conditions that promote the preservation of functional food properties and those where the collapse of the microstructure occurs.

This work reports a characterization of crystallographic phases and chemical composition of hercynite-spinel (FeAl2O4) natural long crystals and their powders using X-ray Diffraction, Scanning Electron Microscopy, Inductively Coupled Plasma mass spectrometry, and mineralographic/petrographic analysis. The samples studied show a high content of hercynite with Neumann bands/Widmanstätten patterns, coexisting with other crystallographic phases such as corundum, spinel (MgAl2O4), esseneite, kamacite, hedenbergite, pseudobrookite, and ulvospinel. The diffractograms of two of the samples examined exhibit an extraordinary sharpness of the diffraction peaks that determines a high degree of crystallinity, which is hard to obtain in hercynite synthesized by artificial methods. In addition, the hercynite natural samples are less porous than the artificially synthesized hercynite. The x-ray diffraction pattern of one of the pulverized crystalline samples allowed us to estimate the percentage of the main phases present. The crystallographic existent phases with the highest participation in one of the spinel samples were hercynite (43.4%), corundum (18.7%), spinel (18.4%), esseneite (17.2%), and kamacite with a 2.3 %. These results contribute to the structural characterization of this unique material widely used in many technological applications.

Para mitigar la corrosión aeroespacial, se sintetizó espinela MgAl₂O₄ por sol-gel usando nitratos de magnesio y aluminio. Este recubrimiento se depositó por inmersión sobre una aleación de níquel a 800 °C. La caracterización mediante difracción de rayos X y microscopía electrónica confirmó una fase cristalina y óxidos térmicamente crecidos que mejoran la resistencia a la oxidación del sistema. DOI: https://doi.org/10.54167/finguach.v2i4.2164