Universidad Autónoma de Ciudad Juárez

The dielectric behavior of lead-free ferroelectric ceramics has garnered significant attention due to growing environmental concerns. In the present study, it is demonstrated that combining sol–gel-derived ceramic BNKT-ST powders with three distinct sintering techniques enables controlled tuning of dielectric properties within a defined range, where diffused phase transition (DPT) has been identified. The techniques employed include pressureless sintering (PLS), sinter-forging (SF), and spark plasma sintering (SPS), applied to compacted ceramic powders. Structural characterization was carried out using scanning electron microscopy (SEM) and X-ray diffraction (XRD). It can be observed that DPT peak positions depend on the sintering technique.

Density functional theory (DFT) calculations on spin-dependent transition state (TS) activation energies for hydrodesulfurization (HDS) hydrogenation phase of Co9S8/MoS2 catalyst interface using LST/QST methodology via Halgren-Lipscomb algorithm are reported herein. These calculations were performed on the already studied catalytically active edge sites (Mo-Mo, S-S and Mo-S) of the Co9S8/MoS2 interface. Our study reports correlations between in situ observations, reaction kinetics, TSs activation energies and molecular dynamics. Finally, two additional SP (SP) computational analysis were considered: “+ 1” and “− 1” SP DFT calculation iterations which provided insight into the magnetic nature of the catalytically active sites previously suggested by several authors. Altogether with these SP calculations, electron density difference (EDD) calculations were plotted for initial, transition and final states structures to approximate the EDD redistribution all along the hydrogenation process. These plots allowed us to compare the EDD distribution on the three SP iterations, which helped us to confirm and explain our findings.

This study addresses the growing environmental challenge posed by dyes, which are highly persistent and toxic contaminants that require advanced and sustainable treatment technologies. Zinc oxide nanoparticles (ZnO NPs) were synthesized through a green processing route using Rosa gallica extract as a reducing and stabilizing agent. By varying the extract concentration (2-8% w/v), the synthesis conditions were optimized, enabling the establishment of clear processing-structure-property relationships. XRD confirmed the formation of the hexagonal wurtzite phase, while FTIR, SEM, TEM, UV-Vis, and photoluminescence analyses demonstrated that increasing the extract concentration led to smaller nanoparticle sizes (from 26 to 11 nm), improved size uniformity, and noticeable modifications in optical behavior consistent with quantum confinement effects. The photocatalytic performance of the synthesized ZnO NPs was evaluated against six model dyes, including azo and cationic dyes. The results demonstrated that both extract concentration and the dye molecular structure strongly influence degradation efficiency. Among the samples, ZnO/RC8 exhibited the highest photocatalytic activity, achieving degradation efficiencies of 78-99% for azo dyes and 93-96% for cationic dyes under UV irradiation. These findings highlight the potential of green-synthesized ZnO nanomaterials as functional photocatalysts with tunable properties for environmental applications.

Delamination is a major failure Mode in laminated composites, typically triggered by premature interlaminar matrix cracking and leading to severe structural degradation. To address this, various through-thickness reinforcement strategies have been explored, including three-dimensional woven architecture. Although these designs significantly improve delamination resistance, their industrial adoption stays limited due to reproducibility challenges and the high cost and operational complexity of advanced manufacturing systems needed for controlled through-thickness reinforcement. This study investigates an alternative interlaminar reinforcement method, through-thickness stitching, aimed at enhancing Mode-I delamination resistance of a commercial fiberglass laminate without changing its native architecture. Composites were manufactured using a low-viscosity epoxy infusion system (MAX 1618 A/B) and a [0/90] biaxial fiberglass fabric. An eight-filament polyethylene thread (Ø = 0.12 mm) was introduced in predefined stitch architectures consisting of three longitudinal patterns having two, three, and five continuous stitch lines, referred to as AV, BV and CV samples, respectively. Results show that stitching highly increases Mode-I interlaminar fracture toughness GIC by 0.3808, 0.4152 and 0.5192 kJ/m2 for AV, BV and CV respectively, compared to 0.0265 kJ/m2 for the unstitched composite O, highlighting the strong influence of stitch orientation and spacing on interlaminar performance. But scanning electron microscopy revealed added failure mechanisms in stitched specimens, including localized fiber misalignment of up to 33° and resin-rich regions approximately 0.6 mm in length, suggesting that while stitching enhances delamination resistance, it may also influence other mechanical properties.

Background Although the genus Alouatta is considered a folivore and frugivore species, the consumption of vegetative parts like flowers often represents a considerable percentage of their diet. Flowers are high in tannins and flavonoids, which are beneficial for the animals due to the antioxidant and anti-inflammatory properties. However, there is a notable lack of knowledge regarding the role of flowers in howler’s diet, especially for the specific needs of females. The objective of this study is to gain further insight into the role of flowers for howler monkey females’ diets during lactation. Methods Between 2021 and 2023, we collected data on the feeding behavior of 20 wild Alouatta palliata mexicana females during non-lactation, early lactation and late lactation on the Agaltepec Island, Mexico. Results In 670 contact hours, a total of 1,471 feeding sessions were recorded. From 29 documented feeding items, five were flowers from the trees of Andira galeottiana, Bursera simaruba, Dendropanax arboreus, Gliricidia sepium and Spondias mombin. Documented feeding items were collected and evaluated for their tannin and flavonoid content. The annual weight-based flower consumption was 12.5%, which increased to 30.3% during blooming months. The tannin content of the flower species exhibited considerable variation, with levels ranging from 0 to 2,038.0 µg/g. In contrast, the qualitative evaluation of principal groups of flavonoid content detected a pronounced presence of flavanones in all five species and flavones in three. Notably, early lactating females exhibited a higher consumption of flowers compared to non-lactating and late lactating females. Conversely, the floral tannin intake was the highest in late lactating and lowest in early lactating females. Our findings suggest that dietary choices of howler monkey females are influenced by seasonal flower availability, with polyphenols playing an important role, suggesting physiological and behavioral adaptations in response to reproductive demands.