Tesis
Permanent URI for this communityhttps://hdl.handle.net/11285/345119
Colección de Tesis y Trabajos de grado (informe final del proyecto de investigación, tesina, u otro trabajo académico diferente a Tesis, sujeto a la revisión y aceptación de una comisión dictaminadora) presentados por alumnos para obtener un grado académico del Tecnológico de Monterrey.
Para enviar tu trabajo académico al RITEC, puedes consultar este Infográfico con los pasos generales para que tu tesis sea depositada en el RITEC.
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- Postbiotics from cheese whey: Inactivation methods and biological activity of selected microorganisms(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12-02) Osuna Orozco, Francisco Raúl; García Cayuela, Tomás; emipsanchez; Carrillo Nieves, Danay; García Gamboa, Ricardo; Binetti, Ana G.; School of Engineering and Sciences; Campus MonterreyA postbiotic is defined as a preparation of inanimate microorganisms and/or their components that confer a health benefit to the host, with potential applications for modulating the gut microbiota and managing metabolic diseases. While still understudied, postbiotics are gaining attention for their therapeutic possibilities, particularly due to their longer shelf life and safety profile compared to other biotic options. Many food industries are reusing by-products to create functional food ingredients; however, about half of the cheese whey produced by the cheese industry is still discarded untreated, contributing to significant land and water pollution. This study explores cheese whey as a matrix for producing postbiotics through three inactivation methods: pasteurization, thermal sterilization, and ultrasound inactivation. Four microorganisms were selected and tested, including two commercial probiotics (Lactobacillus acidophilus LA3 and Lactobacillus acidophilus LA5); and two strains from the BIOTEC collection (Kluyveromyces lactis BIOTEC009 and Lentilactobacillus kefiri BIOTEC013) isolated from artisanal milk kefir. The fermentative behavior of these microorganisms in cheese whey was analyzed, and the antioxidant, anti-diabetic, and anti-inflammatory properties of the postbiotic preparations were evaluated through several assays and compared to a control group of the same microorganisms without prior inactivation. These results indicated that the postbiotic preparations exhibited desirable properties, often matching or surpassing the bioactivity of live preparations. The thermal sterilization treatment seems to be especially noteworthy, as it managed to enhance the antioxidant capacity of all strains, while the ultrasound treatment seemed favorable for anti-inflammatory properties. Lactobacillus acidophilus LA3 stood out as the strain with the best bioactivity overall, even with its treatments, although, there was no single combination of strain and treatment that was the best for every assay. A techno-economic analysis was carried out by doing a simulation of an industrial- scale process to produce postbiotics using two inactivation methods, pasteurization and sterilization. The analysis concluded that for the parameters established, the project is environmentally friendly and both scenarios can be financially viable with a payback time of the initial investment of 4-5 years.
- Quantitative insights into cryptocurrency markets: portfolio optimization, risk management, and volatility patterns(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-11-19) Sahu, Sonal; Fonseca Ramírez, Alejandro; emipsanchez; Núñez Mora, José Antonio; Kim, Jong-Min; Amorós Espinosa, José Ernesto; EGADE Business School; Campus Santa FeThis thesis examines the risk characteristics, portfolio optimization, and volatility patterns in cryptocurrency markets, providing insights into the distinctive financial dynamics of digital assets. Across its analytical chapters, this research addresses both the challenges and opportunities posed by cryptocurrencies, which are characterized by high volatility and risk factors that are uncommon in traditional markets. Chapter 3 develops a portfolio optimization framework specifically for cryptocurrency investments, showing that strategic asset allocation can enhance risk-adjusted returns despite the pronounced kurtosis and semi-heavy tails typical of cryptocurrency returns. Findings from various portfolio construction techniques highlight the need for diversification strategies that consider the unique risk profile of digital assets. Chapter 4 assesses the effectiveness of Value-at-Risk (VaR) as a risk assessment tool in cryptocurrency markets, comparing VaR models under conditions of extreme market behavior. The results indicate that traditional VaR models may underestimate risk due to the volatility and heavy-tailed return distributions of these markets, underscoring the importance of alternative approaches such as extreme value theory to capture tail risk more accurately. Chapter 5 investigates calendar anomalies, specifically the day-of-the-week effect, analyzing patterns in cryptocurrency returns that may aid strategic decision-making. Observed day-of-the-week effects were found to be sensitive to market conditions and external events, such as the COVID-19 pandemic, reinforcing the need for continual assessment of temporal trends. The consolidated analysis in Chapter 6 synthesizes insights from each chapter, outlining the distinctive attributes of cryptocurrencies as an asset class and highlighting implications for both investors and policymakers. Comparisons with traditional assets, limitations of current models, and recommendations for future research are also provided. Overall, this thesis contributes to the academic literature and practical applications by enhancing our understanding of cryptocurrency risk management and guiding more resilient portfolio strategies for this evolving asset class.
- Analyzing VR and AR I4.0 technologies for industrial applications: A comparative study and selection approach development(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12-11) Chavez Najera, Daniela Monserrat; Ahuett Garza, Horacio; emipsanchez; Urbina Coronado, Pedro Daniel; Orta Castañón, Pedro Antonio; School of Engineering and Sciences; Campus MonterreyIn recent years, the implementation of immersive technologies such as Virtual Reality (VR) and Augmented Reality (AR) for Industry 4.0 (I4.0) applications has increased considerably. These technologies enable the connection of virtual and real environments focusing on human centered manufacturing. A challenge when implementing immersive technologies in industrial tasks is the lack of clear paths to select the most appropriate technology for specific operations, and the nonexistence of metrics to evaluate the integration performance. Nonetheless, there are trends in the literature that offer insights to conduct the decision making process for selection between immersive technologies, ensuring the suitability of the application. Based on the decision criteria identified in the literature a decision making approach is developed. This thesis also presents the development workflow of three VR/AR applications implemented in Unity Engine for Meta Quest 3 and Hololens 2. These applications are evaluated using overall performance metrics and are analyzed using the proposed approach.
- Three-dimensional bioprinter based on a robotic manipulator for the development of arbitrarily shaped scaffolds for tissue engineering applications(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12) Ayala Roldán, Diana Paola; Chairez Orta, Jorge Isaac; emipsanchez; Alfaro Ponce, Mariel; Navarro Gutiérrez, Manuel; Flores Jiménez, Mariana Sofía; School of Engineering and Sciences; Campus Ciudad de México; Hernández Sánchez, AlejandraThis thesis details the development of a robotic manipulator-based bioprinting system designed to fabricate scaffolds with complex geometries for tissue engineering applications. Incorporating a fivedegree- of-freedom manipulator, the platform addresses limitations of conventional methods, enabling precise and adaptable fabrication. Key technological achievements include: • A robotic manipulator, powered by high-precision servo motors, provides spatial flexibility essential for complex, patient-specific configurations. This expanded range enhances geometries, better mimicking natural tissue structures. • A computer vision system for real-time adjustments, maintaining alignment with the intended design by dynamically tracking the end effector’s position and orientation. This reduces deviations, ensuring high geometric fidelity and structural consistency. • An extrusion mechanism capable of handling bioink with diverse rheological properties, supporting intricate architectures. This flexibility accommodates a broad range of viscosities and structural characteristics. • A control and feedback system that integrates a proportional-integral-derivative (PID) mechanism, stabilizing the robotic arm’s trajectory. This real-time feedback loop enhances positional accuracy, preserving scaffold integrity under varying conditions. This platform exemplifies advancements in fabrication flexibility, precision, and customization, supporting scalable, patient-specific applications in regenerative medicine.
- Biomechanical analysis on newborns using mixed reality(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12-02) Gómez Mercado, Jorge Allan; Fuentes Álvarez, José Rubén; emipsanchez; Beltrán Fernández, Juan Alfonso; School of Engineering and Sciences; Campus Ciudad de México; Bello Robles, Juan CarlosI would like to express my deepest gratitude in this thesis to my core family, for the support during the duration of my masters degree, and all of my professional career. I want to dedicate this thesis too, to my core team which served as a guide in the best and worst times. My principal thesis advisor Dr. Jose´ Rube´n Fuentes Alvarez which has served as a great support in all the theory behind the thesis and all the material support; as well, served as a personal and professional guide along the years to whom I have great gratitude, and to which I would have not reached my current goals without him. Dedicated also, to my co-advisor Dr. Juan Carlos Bello Robles which helped along this thesis serving as a guide of solutions to many problems which originated along this thesis. Special dedicatory to my fellow biomedical engineer Jose´ Andre´s Mart´ınez A´ vila, which did not only aided the creation of this work, but served as a great friend and companion along the years, to whom I can say too that I would not be where I am without him. As well, I want to dedicate this thesis to a set friends which served as pillars along the creation of this work and of my professional path: Dr. Juan Alfonso Beltra´n Ferna´ndez, UST David Tovar, MSc. Abihu´ Audiffred. Overall, I want to thank to the institutions I feel completely grateful to: CONAHCYT, for the economical support along al the thesis and the institution which supported me along all of my professional career with an important scholarship, Tecnolo´gico de Monterrey.
- Quality assessment and validation of digital PCR (dPCR) for grapevine virus diagnosis(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12-11) Hernández Pérez, Daniella María Joselyn; Díaz Lara, Alfredo; emipsanchez; Carrillo Tripp, Jimena; Rodríguez García, Manuel; School of Engineering and Sciences; Campus MonterreyGrapevine is a highly economically important crop in Mexico. However, it can be affected by several pathogens, including viruses that can cause significant crop losses. It is important to identify early the infected plants to manage the disease correctly and prevent economic losses. Traditional detection methods have drawbacks, such as limited sensibility and accuracy. Digital PCR (dPCR) is an innovative method that claims to be more sensitive and reproducible than the routine method for virus identification: quantitative PCR (qPCR). This study assesses reverse transcription dPCR (RT-dPCR) as a method for the detection and quantification of RNA grapevine viruses focusing on grapevine virus A (GVA), grapevine fanleaf virus (GFLV), grapevine leafroll-associated virus 3 (GLRaV-3), and grapevine Pinot gris virus (GPGV). This assessment was performed using positive controls and comparing the limit of detection (LoD) results of RT-dPCR against the results obtained by RT-qPCR. ANOVA results showed that the PCR technique (RT-dPCR or RT-qPCR) and the virus (GVA, GLFV, GPGV, and GLRaV-3) were statistically significant in the results of the comparison of LoD. Furthermore, the replicates were non-significant according to ANOVA, showing high repeatability in both RT-qPCR and RT-dPCR. Tukey test demonstrated that RT-dPCR is significantly more sensitive than RT-qPCR, with a statistically reliable difference of 95% trust, especially in low-viral-load viruses such GPGV, which detection showed also to be statistically different than the other viruses. Additionally, a field study was performed to identify the presence or absence of each virus in 45 grapevine samples evaluated with RT-qPCR and RT-dPCR. Several false negative results were generated by RT-qPCR, which only reported positive results to 62.5% of the GVA infected samples, 85.7% of the samples contaminated with GLRaV-3, 38.9% of GPGV positive samples and for GFLV only 12.5% of the infected samples were identified. These results confirm the effectiveness of RT-dPCR as a sensitive method for RNA virus detection in grapevine, enabling early diagnosis and optimal management of viral infections in grapevine crops.
- Políticas públicas de estado para reducir, controlar y/o intervenir las actividades ilícitas del contrabando en la frontera con Chile y el estado plurinacional de Bolivia(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12) Navarro Tamayo, Adrián David; Torres Estrada, Pedro Rubén; emipsanchez; Rodríguez Ramírez, Héctor; García Garza, Rafael; Escuela de Gobierno y Transformación Pública; Campus Ciudad de MéxicoEl contrabando en la frontera entre Bolivia y Chile se ha convertido en un problema persistente que afecta profundamente a la economía, la seguridad y la estabilidad social del país. A pesar de los esfuerzos por parte de las autoridades bolivianas y de diversas políticas implementadas para combatir esta actividad ilegal, los resultados hasta ahora han sido insuficientes. La magnitud del problema requiere no solo medidas inmediatas para contener el contrabando, sino también un enfoque integral que aborde sus causas subyacentes y sus implicaciones a largo plazo. Las autoridades bolivianas y los gobiernos, a través de sus políticas, luchan contra el contrabando con el fin de recaudar impuestos aduaneros y proteger la producción nacional, objetivos que no se han cumplido a cabalidad hasta la fecha. Abordar el contrabando en la frontera entre Chile y Bolivia es esencial para garantizar el desarrollo económico, la justicia social y la seguridad nacional. Este esfuerzo no solo es necesario para preservar la soberanía y seguridad del Estado Plurinacional de Bolivia, sino también para promover un comercio justo, equitativo y libre de actividades ilícitas. En última instancia, esta investigación tiene como finalidad contribuir al desarrollo de políticas públicas que fortalezcan la integridad económica y social del país, mejorando la calidad de vida de sus ciudadanos y garantizando un futuro más seguro y próspero para todos. La implementación de políticas públicas efectivas en esta área es fundamental para garantizar la estabilidad y el desarrollo del país. Además de abordar los desafíos inmediatos del contrabando, estas políticas deben considerar el fortalecimiento de las instituciones, la promoción de la formalización económica y la mejora de las condiciones de vida en las comunidades fronterizas. De esta 2 manera, se podrá construir un entorno más seguro y justo, donde el comercio legal prospere y las actividades ilícitas sean significativamente reducidas. Finalmente, la problemática del contrabando en la frontera entre Bolivia y Chile requiere una atención urgente y un abordaje integral. Esta tesis busca ofrecer una contribución significativa en este sentido, mediante un análisis riguroso y la propuesta de políticas públicas bien fundamentadas y efectivas. Solo a través de un enfoque multidimensional y colaborativo será posible enfrentar y mitigar los efectos del contrabando, promoviendo así un desarrollo sostenible y equitativo en la región fronteriza y en todo el país.
- Evaluation of the effect of welding reparation on fatigue strength of stainless Steel(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12-02) Molina Sánchez, Abraham; Reséndiz Calderón, César David; emipsanchez; Farfán Cabrera, Leonardo Israel; Vega Morón, Roberto Carlos; Hernández Peña, Andys; School of Engineering and Sciences; Campus Estado de México; Vieyra Ruiz, HoracioAISI 304 stainless steel is a widely used material for manufacture of machinery parts in different industries such as food, construction, automotive, naval and mining. Many of the failures of these components are related to fatigue and, in order to adhere to the principles of the Circular Economy, repair is proposed over replacement with a new component. As remanufacturing of mechanical components is a growing trend, it is of utmost importance to generate information about mechanical properties of repaired metallic components. Welding and material deposition processes remain the direct option for repairing damaged metallic components. In this work, a process of welding repair was simulated on a sample of AISI 304 stainless steel to evaluate its effect on fatigue strength. AISI 304 specimens were designed to obtain a high first natural frequency to accelerate the tests. To simulate damage, 1.5 mm deep grooves were made in the flat AISI 304 specimens by conventional milling. The repair process involved filling the grooves with ER 308L steel wire using the gas tungsten arc welding (GTAW) technique. Three orientations of reparation were chosen to evaluate the influence of the direction of principal stress in the endurance of the repaired AISI 304 component. To evaluate fatigue strength of a repaired component, a vibration-based fatigue test was conducted using an electrodynamic shaker. At the end of the fatigue tests, fractured specimens were analyzed using scanning electron microscopy. The results indicate that it is possible to recover up to 78.72% of the useful life of a damaged AISI 304 component repaired by welding, depending on the orientation of the repair relative to the direction of the principal stress. A progressive reduction in endurance was found as the orientation of the repair process varied relative to the principal stress direction. Keywords: WAAM; GTAW; Fatigue strength; Remanufacture; Stainless steel; Vibration fatigue.
- The role of capitalization and character repetition in identifying depression on social Media: a bilingual approach(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-11-24) Burgueño Paz, Luis Humberto; Zareei, Mahdi; emipsanchez; Roshan Biswal, Rajesh; School of Engineering and Sciences; Campus Monterrey; García Ceja, Enrique AlejandroDepression is a mental disorder that affects millions of people worldwide, but a significant portion of the affected people don’t receive adequate treatment. There has been an increasing interest from researchers to detect this condition through social media posts in order to prompt for early treatment. However, most of the research has been focused on the Caucasian Western English-speaking population, limiting the applicability of their findings across diverse cultural contexts. While research has shown the use of nonverbal cues to convey sentiment, their role on depression detection remains under-explored. This thesis aims to assess the effect of nonverbal cues, specifically capitalization and character repetition, on depression detection using datasets both in English and Spanish. This effect was explored through three existing datasets. The first dataset included a collection of Reddit posts and comments in the English language and was selected to assess the effect on a dataset coming from one of the most reputable mental health competitions in Natural Language Processing. The second dataset consisted of a collection of Spanish- language messages from Telegram to verify whether findings in the English language would hold for Spanish. The third dataset, also built from Reddit posts, was used to analyze the impact of these features when classifying by depression severity levels rather than binary labels. Four classifiers were used throughout this research: Logistic Regression, Random Forest, Support Vector Machine, and Neural Network. Overall, the impact of capitalization and character repetition for depression detection was found to be minimal. These features had the most effect on English Reddit data with binary labels, while showing limited impact on Spanish data or when classifying by severity levels. Additionally, models using only character repetition outperformed those relying on capitalization features.
- Semiresorbable orthopedic implant design based on nitinol and magnesium alloy(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-12) Grijalva Pazos, Héctor Jesús; Rodríguez Gonzalez, Ciro Ángel; emipsanchez; Cedeño Viveros, Luis Daniel; School of Engineering and Sciences; Campus Monterrey; García López, ErikaThis project focuses on developing and evaluating a novel orthopedic implantprototype, which combines magnesium-calcium and nitinol through a micro laser welding process. The primary objective is to create a biocompatible, biodegradable scaffold for orthopedic applications, offering an alternative to traditional implants. A series of welding experiments were conducted using a PRECO laser welding machine, where different welding parameters, including laser power and exposure time, were tested to optimize the microhardness and mechanical properties of the welds. The simulation and experimental results were compared to validate the design choices and ensure the scaffold's structural integrity. The microhardness tests indicated that the best results were achieved with 200 watts of power and 18 ms exposure time, creating a prototype scaffold for further testing. Future work includes optimizing scaffold designs and conducting compression and degradation tests to evaluate the implant's mechanical performance and corrosion resistance in physiological conditions. This project aims to contribute to developing advanced, sustainable orthopedic implants with improved performance and biocompatibility.
