Nanostructured Zinc Oxide (ZnO) was deposited on silicon (c-Si) and macroporous silicon (m-PS) using a radio frequency (RF) reactive magnetron sputtering technique. Two RF powers of 60 and 80 W were selected for ZnO deposition on the substrates. Furthermore, the c-Si and m-PS substrate temperatures were kept at 500 and 800 °C, respectively. The morphological, structural, and optical characteristics of the samples were studied using scanning electron microscopy (SEM), an X-ray diffractometer (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence spectroscopy (PL). The SEM images revealed the formation of ZnO nanorods on the c-Si and ZnO nanostructures constituted by the assembly of nanorods. It has been found that the increasing RF sputtering power caused the rise in the residual stress. In addition, the increase in the deposition temperature caused an improvement in the arrangement of the crystals, which was attributed to the decrease in crystal defects.

In the present work, we developed hybrid nanostructures based on ZnO films deposited on macroporous silicon substrates using the sol–gel spin coating and ultrasonic spray pyrolysis (USP) techniques. The changes in the growth of ZnO films on macroporous silicon were studied using a UV-visible spectrometer, an X-ray diffractometer (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). XRD analysis revealed the beneficial influence of macroporous silicon on the structural properties of ZnO films. SEM micrographs showed the growth and coverage of ZnO granular and flake-like crystals inside the pores of the substrate. The root mean square roughness (RMS) measured by AFM in the ZnO grown on the macroporous silicon substrate was up to one order of magnitude higher than reference samples. These results prove that the methods used in this work are effective to cover porous and obtain nano-morphologies of ZnO. These morphologies could be useful for making highly sensitive gas sensors.

Methylene blue (MB) concentrations in residual water were detected using fractional calculus, the Rössler chaotic attractor and laser systems. A Nd:YVO4 nanosecond pulsed laser at 532 nm, with pulse energies ranging from 2 µJ to 7 µJ, was applied to irradiate different water samples containing MB concentrations from 20 µl to 100 µl. Fractional calculus was employed with the purpose of modeling the temperature distribution in the samples, with the Caputo fractional derivative describing photothermal effects induced by laser irradiation. Different MB concentrations were detected by using the Rössler chaotic attractor, it monitored variation on concentrations, associating attractor shapes with MB concentrations. Lower concentrations showed a weaker attractor response, whereas higher concentrations manifest stronger attractor shapes in magnitude. Raman spectroscopy confirmed the detection of MB in residual water from the Requena dam, located in Tepeji del Río de Ocampo, Hidalgo, Mexico. The application of fractional calculus improved the prediction of heat distribution in the samples, by incorporating numerical simulation. The results suggest that this approach is suitable for real-time monitoring, as it associates MB concentrations with distinct chaotic attractor shapes. This technique shows promise for the detection of other contaminants as well. Future research should focus on refining this method and expanding its application to develop innovative monitoring solutions.

Las revistas depredadoras representan una problemática importante dentro de la comunidad científica y académica, se caracterizan por trabajar bajo principios carentes de ética, en donde su principal interés es obtener beneficio económico muy a pesar de la falta de calidad en las revisiones al aparentar ser realizadas por pares académicos. Dado lo anterior y como principal objetivo del estudio es validar y determinar el nivel de confiabilidad del instrumento de medición que permite descubrir si la comunidad científica esta frente a una revista depredadora, presentando ítems facultados para descubrir los puntos relevantes de éstas. Por lo que el instrumento de medición propuesto se valida por juicio de profesionales expertos, teniendo una buena aceptación en la construcción, además se analizó la relevancia de los ítems una forma estadística considerando su media, desviación estándar, y correlación por bloque encontrando que el ítem 4 guardó una correlación muy baja. El instrumento de medición resultó ser confiable ya que el alfa Cronbach fue de 0.81 y al eliminar la pregunta 4 aumentó a 0.84 obteniendo un instrumento confiable. Finalmente se presenta un instrumento definitivo robusto con 14 ítems.

This study investigates the reduction of optical losses in periodic/quasiperiodic structures made of porous Si-SiO₂ through a dry oxidation process. Due to their unique optical properties, these structures hold great promise for various optoelectronic applications. By carefully engineering the composition and geometry of the structures, we fabricate periodic/quasiperiodic structures on a quartz substrate using an electrochemical anodization technique and subsequently subject them to dry oxidation at two different temperatures. The structure exhibits two localized modes in the transmission and reflection spectra. Unoxidized and oxidized structures’ complex refractive index and filling factors are determined theoretically and experimentally. Optical characterization reveals that the porous Si-SiO₂ structures exhibit lower absorption losses and improved transmission than the pure porous silicon structures. Additionally, scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) confirm the presence of porous Si-SiO₂ and reduced silicon content. Our study demonstrates that dry oxidation effectively decreases Rayleigh scattering losses, leading to enhanced optical performance and potential applications in efficient optoelectronic devices and systems based on silicon. For instance, periodic/quasiperiodic structures could soon be used as light-emitting devices inside the field of optoelectronics, adding photoluminescent nanoparticles to activate the localized modes.