Adela Eugenia Rodríguez Salazar

This paper presents a design methodology aimed at unconventional users, specifically dogs, in response to the problem of noise pollution. Traditionally, design has favored an anthropocentric approach, focused onto human needs; however, the growing formation of multispecies families requires expanding the scope of action to living beings unable to directly voice their perceptions. In this context, the research proposes a methodological process built upon the interpretation of the owner as a mediator of the animal's responses, by incorporating semi-structured interviews, observational tools, and comparative qualitative analyses (QCA). The proposal is structured in seven different stages. The implementation of QCA is an innovative contribution, as it allows for the evaluation of causative configurations between variables, namely, noise reduction, ornamentation, pet restfulness, as well as ethological training, linking them to improvements in quality of life of the human-dog tandem. Preliminary data shows that the methodology facilitates generating solutions which more efficiently satisfy the animal's real needs, as it is based on behavior as documented by their owners. Also, it addresses the pertinence of accounting for canine auditory well-being and the physiological and behavioral consequences of exposure to loud noises. In conclusion, this methodology proposal contributes to dignifying non-conventional users by means of an adaptable and repeatable framework that transcends anthropocentrism and promotes innovation in contemporary design.

The development of sustainable, high-performance membranes is critical for addressing global wastewater challenges. This study reports the fabrication of novel hybrid electrospun membranes based on polyethersulfone (PES) reinforced with nanocrystalline cellulose (CNC) isolated from pineapple leaf waste and graphene derivatives (GO and TrGO). CNC was successfully extracted via optimized acid hydrolysis, achieving a high crystallinity index of 72.55%. The integration of 0.5 wt.% CNC and 0.5 wt.% TrGO into the PES matrix significantly enhanced the thermal stability and modified the surface chemistry, as confirmed by TGA and FTIR analyses. Nanoindentation revealed a sevenfold increase in mechanical integrity for hybrid systems, while contact angle measurements indicated a transition toward increased hydrophilicity. These findings suggest that the synergistic interaction between bio-based nanomaterials and carbon derivatives offers a robust strategy for enhancing the durability and antifouling performance of synthetic polymer membranes.

Low-temperature direct alcohol fuel cells (DAFCs) represent a pivotal shift toward clean and sustainable mobile power for portable electronics, yet the widespread adoption of current commercial Platinum-based electrodes remains hindered by prohibitive costs and the persistent challenge of carbon monoxide (CO) poisoning, particularly during the Methanol Oxidation Reaction (MOR). While alkaline media can improve kinetics, performance is often limited by slow OH- adsorption and intermediate accumulation. This study evaluates an innovative, green synthesis of Pt, Pd, and PtxPd(10-x) nanomaterials supported on multi-walled carbon nanotubes (MWCNTs), using amphiphilic lignin extracted from corn cob waste as a stabilizer, and compares it with a conventional stabilizer, such as polyvinylpyrrolidone (PVP). The results confirm the formation of a face-centered cubic (fcc) solid solution. Lignin-stabilized catalysts achieved small average particle sizes (2.40 ± 0.6 nm and 3.40 ± 0.6 nm), with the Pt3Pd7-lignin/MWCNTs system exhibiting smaller particles and a higher electrochemical surface area (ECSA) of 222.12 m2 g-1 compared to its counterparts. However, it displayed a lower mass activity (822 mA mgPtPd-1) than the Pt7Pd3-lignin/MWCNTs system (1032 mA mgPtPd-1). The results indicate that lignin is a superior stabilizer compared to PVP, as it more efficiently stabilizes metallic nanoparticles for electrocatalyst production. Overall, electrochemical testing demonstrates that the Pt3Pd7-lignin system offers superior catalytic activity and poisoning tolerance. This is attributed to the hydroxyl groups in the lignin framework, which facilitate methanol access to the active sites. While other binary compositions displayed comparable performance, these results ultimately confirm that repurposing lignin as a stabilizer is both a sustainable green chemistry solution and a high-performance pathway for developing next-generation electrode materials for methanol electro-oxidation.

Low-temperature direct alcohol fuel cells (DAFCs), utilizing stabilized metal nanoparticles, have emerged as clean and sustainable mobile power sources for portable electronic devices. Current commercial Platinum (Pt)-based electrode materials are effective but suffer from high cost and carbon monoxide (CO) poisoning, which significantly limits reaction kinetics, particularly in in the Methanol Oxidation Reaction (MOR). While CO poisoning is typically more severe in acidic media, in alkaline media, the efficiency is often limited by slow OH- adsorption and the incomplete oxidation of intermediates (like formate) rather by carbonate formation. The addition of palladium (Pd) can help to mitigate these disadvantages and improve overall kinetics in alkaline media. Pd facilitates OH- adsorption which promotes the efficient oxidation of adsorbed carbonaceous intermediates (including CO and formate) into CO2 or carbonate, a process crucial for catalyst regeneration. In this study, the amphiphilic structure of lignin extracted from agroindustrial wastes (specifically corn cobs), was evaluated to stabilize Pt, Pd and PtxPd(10-x) nanomaterials (x=0, 3, 5, 7 and 10 wt.%) supported on multi-walled carbon nanotubes (MWCNTs) to be used as electrode materials on methanol oxidation reaction (MOR). The results show that a solid solution is formed with a face-centered cubic (fcc) structure is formed during the synthesis when both noble metals are used. The lignin stabilized catalysts exhibited a small average particle size, ranging between 2.40 ± 0.6 nm and 3.40 ± 0.6 nm. Particularly, the Pt3Pd7-lignin/MWCNTs system (2.40 ± 0.6 nm) was slightly smaller than Pt3Pd7-PVP/MWCNTs system (3.00 ± 0.6 nm). Thus, the electrode materials synthesized using lignin demonstrated superior or comparable electrocatalyst properties for the MOR, including stability in alkaline media. This work confirms that the use of lignin as stabilizer is a viable pathway to efficiently develop novel electrode materials for the electro-oxidation of methanol in alkaline media.

Solid oxide fuel cells (SOFCs) are electrochemical energy conversion devices that directly convert chemical energy into electricity with high-energy conversion efficiency . SOFCs are considered as low environmental impact devices with flexible fuel feeding, low carbon emissions and noise during the working process. Typically, fuel cells require ceramic materials (cathode-electrolyte-anode) that present stability during the oxidation-reduction process (chemical, thermal and mechanical), adequate compatibility with electrolyte, hermeticity, porous structure for the adequate transport of gases to the cell active sites transportation to reaction sites and high electrical conductivity. Unfortunately, the used materials still have significant drawbacks, such as high operating temperatures (800 – 1000 °C), long time required to heat and cool devices during operating cycles, degradation of components, thermal stress, and diffusion between components. To overcome these disadvantages, different perovskite materials have been proposed to reduce the operating temperature between 600-800 °C, but also they reduce the catalytic activity and increase the applied bias on the cathode side, where cell performance plays a key role. Stoichiometric and non-stoichiometric ABX ₃ perovskites have been widely reported as cathode materials for IT-SOFCs. In site A, La, Sr, Ca, Pb, and Pr have been explored, while in B-site cations of Ti, Mn, Ni, Fe, Co and Zr have been reported. The X site is commonly occupied by oxygen with two types of sites, one with coordination six and others with coordination eight or twelve. Among these perovskites, manganites with the general formula of Ln _1-X M _x MnO ₃ (Ln=trivalent rare earth ions, alkaline rare earth element M=3d transition) have been studied with a significant impact on the performance of SOFCs, which can be modulate depending on the ratio of Mn valences (Mn ³⁺ /Mn ⁴⁺ ). This proportion has a direct influence on the performance of electrical and magnetic properties. For example, lanthanum strontium manganite (La _1-x Sr _x MnO ₃ , LSM)-based perovskites showed high electrical conductivities due to distortions in their structures; that is, they are sensitive to the stoichiometry of the perovskite, relating the MnO ₆ structure connectivity and the Jahn- Teller effect which in turn conditions its electron holes. Therefore, perovskite-type manganites are considered the most versatile materials because they show high magnetoresistance, multiferroicity and have reasonable performance both as anode or cathode in IT-SOFCs using different fuels. Although it occurs more severely at high temperatures (> 750 °C) and high cell polarization, even at intermediate temperatures, loss of stability in reducing atmospheres has been observed on the cathodic side of IT-SOFCs devices. This instability causes diffusion and degradation in the cathode-electrolyte interface, with the consequent formation of insulating phases such as La ₂ Zr ₂ O ₇ or SrZrO ₃ , negatively affecting ion conductivity. The total or partial replacement of Sr in the A-site by other lanthanide elements such as Ce, Pr, Nd, Sm, and Gd or with Ca, Co, Cu, and Cr can contribute to the reduction of these disadvantages. For example, a reduction in the mismatch of the thermal expansion coefficient at the electrode-electrolyte interface, a reduction in the cell polarization, and an improvement in overall electro-catalytic activity have been reported. Recently, it has been determined that the electrical and catalytic properties of lanthanum manganite perovskites depend to a large extent on the structure and morphology, but it is necessary to obtain pure phases during the synthesis. In this way, Rietveld’s refinement has been one of the most useful techniques to quantitatively identify the phases and structural changes of this type of material. Ongoing with the proposal of new materials for energy production that help to reduce cathodic polarization resistance and the operating temperatures, in this study, the analysis of different synthesis parameters was carried out to produce pure La _{0.7- x} Pr _x Ca _0.3 MnO ₃ perovskites by lanthanum substitution ( x = 0.35, 0.49, 0.53, 0.56, 0.63, and 0.7) through the Pechini sol-gel method. Rietveld refinement was carried out to evaluate the conditions under which a pure phase can be reached. Additionally, the influence of different Pr contents on the microstructure, phase composition, and electrical conductivity was determined. The results are discussed in terms of potential applications as a cathode electrode for SOFCs.

Diabetic foot ulcers (DFUs) are complex to heal and can lead to amputations and high healthcare costs. To address this, a promising alternative is the creation of electrospun fiber scaffolds for wound dressings. This study fabricated these scaffolds using a blend of natural polymers—chitosan (CTS), polyvinyl alcohol (PVA), and hyaluronic acid (HA)—along with antibacterial silver (Ag) and zinc oxide (ZnO) nanoparticles. The researchers conducted comprehensive analyses, including physicochemical, morphological, and biological assessments. The Ag structures showed potential as microbicidal agent, while the ZnO nanoparticles demonstrated photoactivity and the ability to generate reactive oxygen species (ROS) for antibacterial action. The resulting PVA-CTS-HA-Ag-ZnO scaffolds were found to be both hemocompatible and non-hemolytic, meaning they are safe for use with blood. The cytotoxicity evaluation using the ISO 10993-5 standard showed that the incorporation of CTS and HA decreased cytotoxicity of pure PVA, obtaining non-cytotoxic scaffolds (viability > 70%). Electrospun scaffolds composed with Ag-ZnO NPs in 50-50 and 70-30 ratios also maintained this biocompatibility, while the 30-70 ratio (Ag-ZnO) showed a cytotoxic effect, suggesting a ZnO concentration-dependent effect. These findings confirm that these materials are suitable for supporting skin cell regeneration, having a high potential for use as interactive dressings for treating chronic wounds.

This work explores the synthesis of biomass-waste-derived cellulose nanocrystal hydrogel from aloe vera bagasse (AVB) and banana pseudostem (BPS). A wide variety of synthesis parameters such as acid concentration (45 wt.% and 55 wt.%), temperatures in the process of 25, 40, 45 and 50 °C, and reaction times of 30 and 60 min were analyzed during the acid hydrolysis to evaluate changes in the morphology, crystallinity, swelling, degradation temperature, and mechanical properties. The parameters that most influenced the crystallinity were the temperature and reaction time, showing good characteristics such as percentage crystallinity (89.66% for nanocellulose from C₄₅t₃₀T₅₀ up to 97.58% for CNC-BPS C₅₅t₃₀T₅₀), and crystal size (from 23.40 to 68.31 nm), which was worth considering for hydrogel synthesis. Cellulose nanocrystalline hydrogels from both biomass wastes can modify the crystallinity for tailored high-end engineering and biomedical applications, although using BPS obtained the best overall performance; also, properties such as swelling capability at pH = 4 of 225.39% for hydrogel C₅₅t₃₀T₂₅ (H7), porosity (60.77 ± 2.60%) for C₄₅t₆₀T₄₀ (H6), and gel % (86.60 ± 2.62%) for C₅₅t₆₀T₅₀ (H8) were found. The mechanical test revealed a tensile strength at maximum load of 707.67 kPa (hydrogel H6) and 644.17 kPa (hydrogel H8), which are properties conferred by the CNC from BPS. Overall, CNC from BPS is recommended as a reinforcement for hydrogel synthesis due to its good mechanical properties and functionals, making it a promising material for biomedical applications.

This study aims to create a reference framework to evaluate the technological capabilities (TCs) of public research centers in Mexico through their characterization, measurement, and statistical analysis for decision making on technological strengthening. Additionally, the study seeks to understand the context in which innovation and linkage activities occur within the research system and highlight the importance of integrating such studies into academic institutions. Using this generic framework, public research centers (PRCs), in addition to identifying weaknesses in the development of capabilities at the organizational level, could determine the level of development at which their TCs are located to address social demands and promote collaboration models between university and industry. To achieve this objective, 228 surveys were carried out per stage among researchers from the PRCs in Mexico. Each stage was composed of one questionnaire. Questionnaire 1 considered aspects of investment capabilities, assimilation, modification, support, and linkage. Questionnaire 2 was used to collect data on scientific productivity based on evaluation criteria established by the National Council of Humanities, Sciences and Technologies (CONAHCyT). The aspects covered included infrastructure, scientific publications, intellectual property, postgraduate programs, and collaborative projects. The results indicate that the majority of Mexican PRCs have developed basic and intermediate TCs, with 77% involved in applied research and technological development, but from the total research projects, only 8% present higher levels of technological maturity. The originality of the study lies in the quantitative measurement of TCs within the Mexican PRCs for the benefit of innovative and high-performance work systems, addressing a gap in the existing literature, and could be extrapolated to other universities of developing countries.