Theses & Dissertations

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This collection is exclusively made up of theses, dissertations, and project reports submitted as a requirement for completing a graduate degree at UPR-Mayagüez. If you are a UPRM graduate student and you are looking for information related to the deposit process, please refer to https://libguides.uprm.edu/repositorioUPRM/tesis

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Now showing 1 - 5 of 3013
  • Publication
    Influencia de la motivación en la L1 y L2 de los estudiantes puertorriqueños
    ( 2024-05-07) Rodríguez Rúa, Melissa ; Morales Reyes, Alexandra ; College of Arts and Sciences - Art ; Rivera, Rosita L. ; González, Melvin ; Department of Hispanic Studies ; Hernández , Itza
    The present research examined the levels of motivation towards the mother language, Spanish, and second language, English, of 29 Puerto Rican students located in a public school in the southern area of Puerto Rico, considering variables such as international posture, ideal self in L1/L2, instrumental motivation and intrinsic motivation. These dimensions were measured through two questionnaires. In addition, questions were analyzed, at the demographic level, to measure socioeconomic level and observe whether it has any impact on the dimensions studied. The results reveal that, in general, students show high levels of motivation. However, when evaluating the effects of the student’s socioeconomic level on the variables, significant differences were found in instrumental motivation. These findings highlight the importance of continuing to strengthen language skills in Puerto Rican students, as well as promoting a positive attitude toward the languages that converge on the island to achieve better educational and personal development.
  • Publication
    Creación y validación de estructuras de datos para aproximar EDP con diferencias finitas en mallas adaptativas
    ( 2024-05-10) Ordóñez Rodríguez, Claudia Patricia ; Castillo, Paul E. ; College of Arts and Sciences - Sciences ; Rúa Alvarez, Catalina M. ; Narciso Farias , Flor ; Department of Mathematics ; Hernández Hernández, Carlos I.
    Diferentes aplicaciones relacionadas con la física pueden ser modeladas matemáticamente por Ecuaciones Diferenciales Parciales (EDP) como la ecuación de Poisson. Este tipo de ecuaciones con condiciones frontera de Dirichlet y Newmann en el caso bidimensional son aproximadas con métodos numéricos como el método de Diferencias Finitas (DF), especialmente en Mallas con Refinamiento Adaptativo (AMR, abreviatura en inglés de Adaptive Mesh Refinement) en regiones específicas por sus posibles restricciones en su solución. En esta investigación se lleva a cabo un estudio teórico y computacional de la discretización del problema de Poisson en 2D de forma matricial utilizando el método de DF, tanto en mallas uniformes como en AMR. Se emplean estructuras de datos como Tabla de dispersión (HT, abreviatura en inglés de Hash Table) para representar las células de la malla, lo que implica un análisis detallado de las características de estas estructuras, así como las de sus operaciones y su complejidad computacional. Además, se muestra una variación de métodos de interpolación que permiten la comunicación de las células de los diferentes niveles. Entre los resultados obtenidos, se verifica la convergencia y se realiza un estudio de diferentes propiedades de la matriz como número de condicionamiento, patrón de esparcidad, que se refiere al gráfico de puntos de elementos no nulos de las matrices dispersas, y relación de la interpolación aplicada. Adicionalmente, se lleva a cabo una generación de AMR con varios criterios de refinamiento, mostrando un análisis de eficiencia y de colisiones para las HT.
  • Publication
    Improving surface-enhanced Raman scattering by the implementation of pillararenes on silver nanoparticles
    ( 2024-05-09) Vázquez Pérez, Germán ; Bezares, Francisco J. ; College of Arts and Sciences - Sciences ; Marrero-Soto, Pablo J. ; Sánchez Quintero, Dilsom ; Department of Physics ; Cabrera Ríos, Mauricio
    Surface-enhanced Raman Scattering (SERS) spectroscopy is a highly sensitive and specific detection method. This technique is useful for sensing extremely small concentrations of analytes, that could be harmful for human health and food security. Therefore, it is of foremost importance to study methods that can enhance the sensing capabilities of SERS. This work presents an experimental and statistical analysis of optimal parameters for the synthesis of metallic nanoparticles, which are responsible for the enhancement of the Raman signal. After the parameter optimization, a layer of dimethoxy pillar[5]arene was deposited onto the Ag nanoparticles to study the selectivity of the technique. These are highly symmetric macrocycles that have the capacity to attract certain types of molecules into their central cavity. The layer of pillar[5]arenes was optimized for concentration and thickness, which allowed studying their capabilities to capture toxic analytes and detect them using SERS.
  • Publication
    Dinah's rape as narrative and ideological crossroads: A revisionist critique and alternate outcome
    ( 2024-05-14) Rivera Betancourt, Loida E ; Stephen, Gregory K. ; College of Arts and Sciences - Art ; Irizarry Rodriguez, Jose ; Cordero Rios, Hugo ; Department of English ; Rodriguez, Grisell
    Dinah’s Alternative Narrative was developed as an exercise for writing fiction starting with the Bible as literature. The story presents a different ending: the marriage of Dinah and Shechem. This alternative outcome provides a rescue of Dinah’s voice, that empowers her to decide what to do with her life and with whom. The narrative reverses the misogynistic and xenophobic intervention of Dinah’s brothers. I consider this story as a watershed in Hebrew identity as held by the Priestly/Redactor version of Genesis 34 that has been regarded as the official version. Dinah’s empowerment as qedeshah is a challenge thrown to a term in ancient Israel weighted with misconceptions and prejudice created by the Priestly/Redactor in a Deuteronomic context, against the cultic functions of these women and exclude them from Temple service. To convey a plausible and realistic narrative, I considered the latest biblical scholarship, including feminist studies, archeological, ethnographic, and linguistic inputs
  • Publication
    Study of the electric interactions in peptide-membrane interaction using molecular dynamics simulations
    ( 2024-05-09) Quintana Jaramillo, Thalia ; Ramos, Rafael A. ; College of Arts and Sciences - Sciences ; Roura Dávila, Erick A. ; Santana-Colón, Samuel ; Department of Physics ; Quintero Mendez, Raiza R.
    Inducing an increase in the permeability of biomembranes has become an attractive alternative for developing new treatments against cancer cells or bacteria. Two techniques to increase permeability are: through the application of electrical pulses, known as electroporation, or by facilitating the interaction of active peptides with biomembranes. Electroporation, however, has been limited by the need to apply high electric fields or prolonged exposure periods to achieve effective permeabilization, which can trigger significant side effects. On the other hand, understanding the mechanism of action of active peptides has presented challenges, making their design and implementation difficult. In the literature, it has been reported that the combination of cationic active peptides with electric pulses can reduce the intensity of the electric field required for membrane permeabilization. Nevertheless, the reasons behind this phenomenon have not yet been thoroughly explored. Based on this observation, we have used molecular dynamics simulations to investigate how the presence of a cationic peptide, specifically Cateslytin, can modify the impact of the electric field in the electroporation process. We found that when electrostatic interactions between the heads of the lipids and the cationic peptides, or ions, favor the reorientation of the lipid dipoles towards the direction of the field, the membrane permeabilization process occurs rapidly; thus, we suggest that this could explain the need for a lower intensity of the electric field.