Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Photocatalytic activity of chemically deposited ZnO and TiO₂ nanostructured thin films in methyl orange degradation(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-06-09) Lara Garcilazo, Israel Iván; Karthik Tangirala, Venkata Krishna; emipsanchez; Hernández Zanabria, Angélica Guadalupe; Cano Quiroz, Anaid; Arvizu Coyotzi, Miguel Ángel; School of Engineering and Sciences; Campus Estado de México; Maldonado Álvarez, ArturoWater pollution caused by synthetic dyes, such as Methyl Orange (MO), represents an environmental concern due to their negative impacts on the environment and human health. The removal of these pollutants represents a challenge due to their chemical stability and resistance to conventional water treatment methods. Addressing these problems requires the development of photocatalytic materials capable of degrading this persistent pollutant. This project tests the photocatalytic activity of ZnO and TiO2 films by degrading MO solution (additionally, ZnO is used for the photodegradation of Levonorgestrel). ZnO thin films were deposited using Dip Coating and Ultrasonic Spray Pyrolysis to study the effect of precursor concentration, Ni doping, precursor milling and deposition method. Additionally, TiO2 samples were deposited only by Dip Coating to study the effects of the precursor used (titanium butoxide or titanium isopropoxide) and the water to titanium precursor ratio. The synthesized films were characterized by FTIR, XRD, SEM and UV-Vis spectroscopy. The highest MO degradation efficiency (83.75%) when using ZnO was achieved with ZnO-0.1-DC, which is attributable to its small crystallite size and particle sizes, as well as high dislocation density. Nevertheless, the ZnO thin films performed poorly during the degradation of levonorgestrel. Regarding TiO2 films, TiO2-103-BU-DC performed the best during the MO photodegradation (83.89%), which is attributable to its small crystallite size, high dislocation density and mixture phases (anatase and brookite).
- Prediction of viscoelastic and printability properties on binder-free TiO2-based ceramic pastes by DIW through a Machine Learning approach(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2023-08-15) Pulido Victoria, Luis Antonio; Flores Tlacuahuac, Antonio; emimmayorquin; Bonilla Cruz, José; Hernández Romero, Ilse María; Escuela de Ingeniería y Ciencias; Campus MonterreyPrintability, a key factor in the success of Additive Manufacturing (AM) processes, relies on various aspects, including material properties and process parameters. This study aims to explore the relationship between the rheological properties of binder-free TiO2-based ceramic pastes and their printability using a machine learning approach, specifically utilizing a feedforward Deep Neural Network (DNN) model. The main objective of this thesis is to develop a predictive model that can accurately estimate the printability of binder-free TiO2-based ceramic pastes based on key rheological properties. To achieve this, a comprehensive dataset consisting of 25 samples of rheological properties and corresponding printability assessments was collected and used for model training and evaluation. The methodology involved the collection of rheological and viscoelastic data for a range of TiO2-based ceramic pastes including shear viscosity (η) values as a function of shear rate (γ_ ), and storage (G0) and loss (G00) modulus values as a function of oscillatory stress (σ). Rheological properties (γ_ and η) were then utilized as input features for the feed-forward DNN model, while the viscoelastic data (G0 and G00) was set as the target properties. The model was trained using a portion of the dataset, and the remaining set was utilized for testing. No validation set was defined due to the small size of the dataset. The results obtained from the developed model not only demonstrated a correlation between the rheological properties and printability of the studied ceramic pastes but also revealed a relationship between the rheological and viscoelastic behavior of the samples, providing deeper insights into this ceramic system. The predictive capabilities of the model were evaluated based on performance metrics such as Mean Squared Error (MSE) and Relative Error ( ). The discussion section provides a detailed analysis of the findings and explores the limitations of the study, such as the sample size and potential influence of the experimental work on the model’s performance. This thesis contributes to the field of AM by presenting a machine learning-based approach for predicting the printability of binder-free TiO2-based ceramic pastes. The DNN model proves to be a valuable tool for assessing the printability of the pastes. Moreover, it provides further insights into the ceramic system by correlating rheological and viscoleastic properties. This research opens up possibilities for optimizing paste formulations and process parameters to enhance the additive manufacturing of ceramics. Furthermore, the model here proposed may serve as starting point for exploring alternate machine learning algorithms, such as transfer learning, generative networks and even Bayesian optimization.
- Kinetic modeling of the photocatalytic degradation of acetaminophen and its main transformation product using TiO2 nanotubes(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-06-15) Delgado Juárez, Jocelin Alí; LOPEZ ZAVALA, MIGUEL ANGEL; 37056; López Zavala, Miguel Ángel; emipsanchez/puemcuervo; García Orozco, Jorge Humberto; Monarrez Cordero, Blanca Elizabeth; School of Engineering and Sciences; Campus MonterreyIn this study, a kinetic model of the heterogeneous photocatalytic degradation of acetaminophen (APAP) and its main transformation product is presented. The mechanistically kinetic model incorporated the modeling of the radiation field in the reactor with a Monte Carlo simulation. Experiments were carried out in a reactor operated in batch mode, with the use of TiO2 nanotubes as photocatalyst and an irradiation at 254 nm (UVC). Kinetic parameters were estimated from the experiments by applying a non-linear regression procedure. Later, the intrinsic expressions to represent the kinetics of APAP and its main transformation product were derived. The predicted results of the kinetic model show a concordance with the experimental data, however, experimental results showed that most of the APAP degradation was due to a photolytic process and not due to a photocatalytic process. Since the photolytic process was not incorporated into the model, it is necessary to adjust the proposed kinetic model for incorporating photolytic radiation; or the proposed model could be adjusted for the evaluation of the photocatalytic degradation of another drug that does not have photolysis under UVC.
- Toxicological evaluation of the TiO2 anatase and rutile crystalline phases in H9c2 cardiac cells(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-12-05) Santos Aguilar, Pamela; CONTRERAS TORRES, FLAVIO FERNANDO; 132171; Contreras Torres, Flavio Fernando; emipsanchez; Lozano García, Omar; Silva Platas, Christian Iván; Salas Treviño, Daniel; School of Engineering and Sciences; Campus Monterrey; García Rivas, Gerardo de JesúsAlthough TiO2 particles constitute a highly used material in consumer products, including food and pharmaceutical industries, considerable experimental evidence suggests that TiO2 particle exposure could be harmful and cause adverse health effects. Generally, the most studied factor for toxicity is size as nano, and fine particles are considered more toxic than bulk forms. The second structural factor most studied is the crystalline phase. The TiO2 rutile phase is considered a more inert phase than the highly active, high-refractive-index anatase phase. The cytotoxicity of TiO2-anatase has been related to that these particles can induce higher production of reactive oxygen species (ROS), which is a trigger of apoptosis pathway and alteration of mitochondrial membrane potential in cells. However, such a toxicological susceptibility to the TiO2-anatase phase may differ from the one initiated by the TiO2-rutile phase, suggesting a different cell death mechanism, which is not known at the detail. In this thesis, a series of experimental measurements were carried out to analyze TiO2-anatase and TiO2-rutile submicron-sized particles' physical properties. The TiO2 particles in anatase phase were transformed to rutile phase through a heating process, and then both were analyzed by Raman spectroscopy, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), dynamic light scattering (DLS), and zeta potential. The evaluation of the toxicity of TiO2 particles in H9c2 cardiac cells to identify the role of the crystalline phase that may pose a health risk in a dose-dependent manner is the main objective of this study. The TiO2-anatase and TiO2-rutile particles' toxicity assessment was conducted in vitro, evaluating the metabolic activity, the plasma membrane integrity, mitochondrial superoxide production, and intracellular redox state. The particles' characterization by XRD and Raman spectroscopy confirmed the successful transformation of anatase particles to the rutile phase through a heating process. By DLS, it was confirmed that the hydrodynamic particle diameter was 166 nm and 468 nm for anatase and rutile, respectively. At the same time, further analysis by XLPA methods: Williamson-Hall and Warren Averbach showed that the apparent crystallite size of anatase is larger than for rutile. SEM microscopy identified that anatase particles had a spheric-like shape while for rutile were slightly more elongated. H9c2 cells show metabolic activity inhibition of 50% at an approximate value of 30 μg/mL when exposed to either anatase or rutile particles for 24 h. However, the dose-dependent inhibition at lower or higher values of the IC50 is dependent on the crystalline structure. Neither anatase phase nor rutile phase reduces the number of viable cells through necrosis; however, cell death has been categorized as early or late apoptosis for both particles. No significant alteration of the intracellular redox state at any particle exposure concentration between 0.3 μg/mL – 30 μg/mL was observed. On the other hand, for anatase, a 3-fold increase in mitochondrial superoxide production at 30 μg/mL was found, indicating that the intrinsic mitochondrial apoptotic pathway might mediate the apoptosis. However, for rutile, there is no increase in mitochondrial ROS production, suggesting that the cell death mechanism is dependent on a different metabolic pathway independent of the mitochondria.
- Processing and characterization of UHMWPE-TiO2 nanocomposites for the development of a zygomatic bone prosthesis manufactured by SPIF(Instituto Tecnológico y de Estudios Superiores de Monterrey) Ortiz-Hernández, Rodrigo; https://orcid.org/0000-0003-0735-8577; Elías-Zúñiga, Alex; Olvera-Trejo, Daniel; Campus Monterrey; Martínez-Romero, OscarIn the past years the use of nanotechnology for the development of new composite materials had become one of the most trending topics in the scientific community. Researchers around the world are working hard to prove that the addition of small quantities of nanoparticles (NPs) can be the differentiator that might change completely the way materials are seen nowadays. This master’s program thesis focuses on bringing to medical disposition a novel material for craniofacial prosthesis capable of satisfying several of the biggest medical issues reported today in hospitals all over the world. In particular, the use of the developed UHMWPE-TiO2 nanocomposite is, but not exclusively, aimed to be the principal material in the manufacture of a functional zygomatic bone prosthesis. For achieving this goal, UHMWPE-TiO2 sheet nanocomposites were prepared using incipient wetting and compression molding processes at different concentrations (0.25 wt. %, 0.5 wt. %, 0.75 wt. % and 1 wt. %). Positive results were obtained through the dispersion of the TiO2 NPs in a liquid solution observed at low concentrations (<0.75 wt. %). At higher concentrations, micro scaled agglomerations of NPs were seen with the use of SEM images which exhibit that the saturation point of TiO2 NPs inside the polymeric matrix is situated between 0.75 wt. % and 1 wt. %. The degree of crystallinity and structural properties of the developed nanocomposites were investigated by X-ray diffraction and differential scanning calorimetry, the results presumes that the compression molding manufacturing procedure inhibits the normal crystallization phenomena of UHMWPE. It was observed the reduction in symmetry for the orthorhombic unit cells, found in(110) and (200), to monoclinic structures (001). Furthermore, FT-IR revealed the appearance of carbon-oxygen vibrational modes at 1740cm−1 (C=O) and 1250cm−1 (C-O) assuring a positive dispersion of TiO2 NPs inside the polymeric matrix. Tensile tests and single point incremental forming processes were carried out indicating the enhance of the mechanical properties of the UHMWPE-TiO2 nanocomposite superior to recent publications. Biological activity was analyzed using LIVE/DEAD Cell viability assays with favorable results showing almost null cytotoxicity. Finally a personalized, bio compatible, inert, resistant, cheap and light weighted zygomatic bone graft was crafted and mounted in a real partially damaged skull.