This study evaluated the corrosion inhibitory effects of Ruta graveolens leaf extract for 304 stainless steel in 1 M HCl. The analysis of the leaf extract using HPLC indicated that the primary compounds present in the leaf extract were rutin, caffeic acid, p-coumaric acid, and apigenin. The inhibition efficiency (IE%) of the extract was studied using weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and computational simulation (density functional theory, DFT). The effects of the inhibitor concentration and solution temperature were investigated. The results indicated that the IE% increased for increasing concentrations of the extract, while the reverse was true with increasing temperatures. At 25 °C and a 600 ppm extract concentration, the results indicated a maximum inhibition efficiency of 95%, 98%, and 96% by weight loss, potentiodynamic polarization, and EIS techniques, respectively. SEM observations showed a significant change in the surface morphology of the 304 SS with and without the addition of the inhibitor compound. At all temperatures, the adsorption of the inhibitor components onto the 304 SS surface was found to follow the Langmuir isotherm model, and the inhibition process was governed by physical adsorption. Furthermore, chemical interactions between the inhibitor and the 304 SS steel surface were elucidated via density functional theory (DFT) calculations.
The integration of biogas and photovoltaic solar energy systems in sanitary landfills represents a promising strategy for sustainable energy generation and efficient urban waste management. This study evaluates the potential for biogas and photovoltaic energy production in two cells of the Municipal Landfill of Chihuahua, Mexico. Using the LandGEM and MMB models (Landfill Gas Emission Model and the Mexican Biogas Model), biogas generation was estimated by considering the composition of the landfill gas and the characteristics of the cover in each cell, revealing notable differences due to their operational periods and waste deposition. Photovoltaic simulations, conducted with the HelioScope software 2020, evaluated spatial configurations and solar radiation data. The generation potential for 2025 was simulated using predictive models, yielding results between 25.48 and 26.08 MW for the biogas–photovoltaic system, depending on the orientation of the panels and the optimization of the coverage. The novelty of this work lies in the combined evaluation of biogas and photovoltaic potential within a single landfill site, integrating advanced modeling tools to optimize system design. By demonstrating the feasibility and benefits of this hybrid system, the study contributes to clean energy solutions, environmental mitigation, and improved waste management strategies. Our findings emphasize the importance of site-specific management practices and predictive modeling to enhance renewable energy production and reduce greenhouse gas emissions, supporting sustainable urban development initiatives.
In recent years, there has been a surge in the extrusion-based 3D printing of materials for various biomedical applications. This work presents a novel methodology for optimizing extrusion-based 3D bioprinting of a gelatin/siloxane hybrid material for biomedical applications. A systematic approach integrating rheological characterization, computational fluid dynamics simulation (CFD), and machine-learning-based image analysis, was employed. Rheological tests revealed a shear stress of 50 Pa, a maximum viscosity of 3 × 105 Pa·s, a minimum viscosity of 0.089 Pa·s, and a shear rate of 15 rad/s (27G nozzle, 180 kPa pressure, 32 °C temperature, 30 mm/s velocity) for a BIO X bioprinter. While these parameters yielded constructs with 54.5% similarity to the CAD design, a multi-faceted optimization strategy was implemented to enhance fidelity, computational fluid dynamics simulations in SolidWorks, coupled with a custom-develop a binary classifier convolutional neuronal network for post-printing image analysis, facilitated targeted parameter refinement. Subsequent printing optimized parameters (25G nozzle, 170 kPa, 32 °C, 20 mm/s) achieved a significantly improved similarity of 92.35% CAD, demonstrating efficacy. The synergistic combination of simulation and machine learning ultimately enabled the fabrication of complex 3D constructs with a high fidelity of 94.13% CAD similarity, demonstrating the efficacy and potential of this integrated approach for advanced biofabrication.
In this study, Streptococcus mutans bacteria were tested on nickel–titanium archwires in the presence of silver nanoparticles (AgNPs) as coatings. As a growth control, a well containing the BHI broth and bacterial suspension without silver nanoparticles was inoculated. The test was carried out in triplicate. The NiTi archwires in the presence of artificial saliva were incubated at different exposure times between 0–24 h and 15–30 days, respectively. The archwires were then put in contact with S. mutans to evaluate the AgNPs bactericidal effect. The characterization of AgNPs with NiTi archwires was conducted using scanning electron microscopy (SEM), X-ray energy dispersive analysis (EDS), fast fourier transform (FFT), power spectral density (PSD), surface geometry analysis, metal relation analysis, and control process analysis. The results indicate that the bioelectric signal and chemical interaction of NiTi and Ag nanoparticles have an antibacterial effect. In this context, the high wavelength of 17.06 mm and the wave amplitude of 15.66 GL are representative of the light scattering and humidity of the system in which the bacteria and silver nanoparticles interact. The sizes of the Ag nanoparticles in the archwires were less than 150 nm. Under microaerophile conditions, the solution’s pH and temperature were 7.0 at 37 °C, respectively. The NiTi archwires AgNPs functionality and relation to the minimum inhibitory concentration, dominant wavelength in power spectral density, and fast fourier transform analyses were investigated. The analysis was of the interaction between the high and low frequencies of the AgNPs-NiTi archwires and the S. mutans bacteria. This approach opens up a new route for the assessment and management of bacterial growth in various fluids by utilizing alternative biologically acceptable materials.
Hydroxyapatite nanoparticles compounds were synthesized. Natural hydroxyapatite and a linear polysaccharide (1–3 linked β-D galactopyranose and 1,4 linked 3,6 anhydro-α-L-galactopyranose) were used as a precursor in its formation. Our purpose was to produce nanoparticles in the presence of a linear polysaccharide with the use of a gelification method. The powder sample was evaluated by scanning tunneling microscope (STM), Brunauer-Emmett-Teller (BET) analysis, X-ray diffraction pattern (XRD), differential thermal analysis (DTA), infrared (IR) analysis, and thermal gravimetric analysis (TGA). According to the results, it was found that these nanoparticles can successfully be synthesized using a polysaccharide in a solution. On the other hand, the XRD peak intensity corresponds to hydroxyapatite structure in the range of temperature of 810°C. The influence of the polysaccharide on the evolution of the nanoparticles has been demonstrated. This observation opens up new routes for the fabrication of nanoparticles using polysaccharides network. The synthesized nanoparticles have diameters ranging from 10 nm to 11 nm approximately. The elaboration conditions such as pH and concentration were optimized in this solution.
Olive-like TiO2 (titanium dioxide), nanospheres compounds were synthesized. Polysaccharide (1–3 linked β-D galactapyranose and 1.4-linked 3.6 anyhdro-α-L-galactopyranose and titanium isopropoxide (IV) was used as a precursor in its formation. The powder sample was evaluated by scanning tunneling microscope, X-ray diffraction pattern, power spectral density, fast Fourier transform, differential thermal analysis, continuous wavelet transform, and isotropy texture analysis. The results demonstrate that these nanospheres can successfully be synthesized in a solution using a polysaccharide network by means of the sol-gel method. The synthesized olive-like TiO2 nanospheres have diameters ranging from 50 nm to 500 nm. The synthesis parameters, such as temperature, time, and concentration of the polysaccharide, were controlled in solution.