MnO/ZnO:Zn Thin-Film Frequency Adaptive Heterostructure for Future Sustainable Memristive Systems.

In recent years, advances in materials engineering based on adaptive electronics have found a new paradigm to optimize drawbacks in signal processing. A two-layer MnO/ZnO:Zn heterostructure envisioned for frequency adaptive electronic signal processing is synthesized by sputtering, where the use of internal states allows reconfigurability to obtain new operating modes at different frequency input signals. X-ray diffraction (XRD) analysis is performed on each layer, revealing a cubic structure for MnO and a hexagonal structure for ZnO:Zn with preferential growth in [111] and [002] directions, respectively.

Metal contents in house geckos (Squamata: Gekkonidae) from industrial and urban areas of southern Tamaulipas, Mexico and western Andalucía, Spain, may reflect airborne metal pollution.

House geckos share living quarters with humans in the tropical and subtropical regions inhabited by these reptiles. Gecko behavior, biological traits, continuous exposure to suspended particulate matter 0 µm in diameter (PM) and dust, as well as status as exotic species, motivated the choice of these species to examine environmental exposure to ambient air pollutants, in particular metals, and subsequent accumulation in these organisms. One part of the study was conducted in Tamaulipas (Mexico) where is abundant in urban and industrial environments, the other part was conducted in Andalucia (Spain) where is found in similar environments.

In Situ Growth of Silver Nanoparticles on Chitosan Matrix for the Synthesis of Hybrid Electrospun Fibers: Analysis of Microstructural and Mechanical Properties.

A viable alternative for the next generation of wound dressings is the preparation of electrospun fibers from biodegradable polymers in combination with inorganic nanoparticles. A poly(vinyl alcohol)-chitosan-silver nanoparticles (PVA-CTS-Ag NPs) system has been developed for antimicrobial and wound healing applications. Here, the preparation of PVA-CTS-Ag electrospun fibers using a two-step process is reported in order to analyze changes in the microstructural, mechanical, and antibacterial properties and confirm their potential application in the biomedical field.

CVD Conditions for MWCNTs Production and Their Effects on the Optical and Electrical Properties of PPy/MWCNTs, PANI/MWCNTs Nanocomposites by In Situ Electropolymerization.

In this work, the optimal conditions of synthesizing and purifying carbon nanotubes (CNTs) from ferrocene were selected at the first stage, where decomposition time, argon fluxes, precursor amounts, decomposition temperature (at 1023 K and 1123 K), and purification process (HNO + HSO or HCl + HO), were modulated through chemical vapor deposition (CVD) and compared to commercial CNTs. The processing temperature at 1123 K and the treatment with HCl + HO were key parameters influencing the purity, crystallinity, stability, and optical/electrical properties of bamboo-like morphology CNTs. Selected multiwalled CNTs (MWCNTs), from 1 to 20 wt%, were electropolymerized through in-situ polarization with conductive polymers (CPs), poly(aniline) (PANI) and poly(pyrrole) (PPy), for obtaining composites.

Sugarcane Bagasse-, Orange Peel-Derived Adsorbent Materials: Thermal and Morphological Studies.

In this work, agro-industrial wastes such as sugarcane bagasse and orange peel were used for obtaining activated carbons through phosphoric acid activation in order to propose them as adsorbent materials during the production of carbon foam or filters for wastewater treatment applications. A two-step process was carry out to obtain activated carbons; the first step consisted of a simple physical activation at high temperature 400 °C to reach raw material decomposition; followed by acid activation at temperature of 500 °C. The effect of concentration of acid media (45, 65 and 85 wt.

Fabrication of Sputtered Ce/La, La/Ce Oxide Bilayers on AA6061 and AA7075 Aluminum Alloys for the Development of Corrosion Protective Coatings.

This work provides a comparative study on the corrosion protection efficiency of Ce, La films as well as Ce/La and La/Ce oxide bilayered coatings deposited onto AA7075 and AA6061 substrates by the radio frequency (RF) magnetron sputtering technique. The coating thickness ranged approximately from 12 to 835 nm, which changed with the deposition parameters and substrate composition. The relationship between microstructure, roughness and electrochemical performance is examined.

Stabilized landfill leachate treatment using Guadua amplexifolia bamboo as a source of activated carbon: kinetics study.

In the present study, the characteristics of leachate generated from dumpsite called 'Zapote' located in southern region of Tamaulipas, Mexico were evaluated. The adsorption of non-biodegradable organic matter measured as chemical oxygen demand (COD), color and heavy metals from leachate on activated carbon (AC) prepared in acid media from Guadua amplexifolia bamboo has been studied. In addition, the computation of kinetic parameters during the adsorption process as well as the most probable mechanisms was determined.

Intensification of Electrochemical Performance of AA7075 Aluminum Alloys Using Rare Earth Functionalized Water-Based Polymer Coatings.

This work reports the effect of different amounts of ceria nanoparticles on UV resistance and barrier properties of water-based polyurethane (WPU) on glass and AA7075 aluminum alloy substrates. Hybrid coatings were synthesized from an aliphatic WPU⁻HDI (1,6-hexamethylene di-isocyanate) and cerium oxide nanoparticles (CeO₂) with an average particle size distribution of about 25 nm. Different nanoceria amounts (1, 3 and 5 wt %), mixing times (30, 60 and 120 min) and methods to disperse the nanostructures into the polymer matrix (magnetic stirring and sonication) were evaluated.