Transesterificación de triglicéridos en una columna de contacto líquido-líquido

Objetivo General. Establecer el porcentaje de ésteres metílicos obtenidos mediante la transesterificación de un aceite vegetal en presencia de un catalizador heterogéneo y en una Columna de contacto líquido-líquido-sólido (DLCR), adaptada como reactor con el fin de disminuir la resistencia a la transferencia de masa líquido-líquido-sólido. Objetivos Específicos. Determinar si la cal viva calcinada presenta actividad catalítica igual o superior al CaO grado reactivo en la transesterificación de un aceite vegetal. Establecer el tipo de aceite, entre cártamo y canola, que favorece la producción de ésteres metílicos. Determinar las condiciones de reacción en las cuales se obtiene un mayor porcentaje de ésteres metílicos en un reactor de tanque agitado. Determinar las condiciones de reacción en las cuales se obtiene un mayor porcentaje de ésteres metílicos en una columna de contacto líquido-líquido-sólido. Establecer el modelo cinético que mejor represente la transesterificación del aceite vegetal estudiado. El presente trabajo comprende 4 capítulos principales, además de una sección de referencias y una de anexos. En el primer capítulo se detallan los antecedentes que no solamente ayudan a justificar la realización del presente trabajo sino también a comprenderlo y a discutir los resultados obtenidos. En el capítulo 2 se detalla la metodología para lograr los objetivos arriba planteados. Los resultados obtenidos se presentan y discuten en el capítulo 3 y las conclusiones en el capítulo 4. Las referencias empleadas se presentan en la penúltima sección de este trabajo. Finalmente, en el apartado de anexos se incluyen datos importantes empleados para los cálculos realizados, principalmente. También se incluyen ejemplos representativos de resultados que no se incluyen en el capítulo 3 como cromatogramas. Para mejor comprensión del presente trabajo también se incluye un glosario y finalmente se presenta constancia de presentación de resultados en un congreso internacional y la evidencia de un artículo publicado en una revista indizada.The relevance in recent years for the minimization of polluting gases and the search for alternative energy sources apart from oil, has led research in various forms of renewable energy including power generated by wind, hydro, solar, biomass and biofuels; and among them biodiesel. Despite extensive research related to the production of biodiesel, there are some issues that desserve to be addressed from the point of view of engineering, especially in the efficiency of mass transfer between the two organic phases (methanol and oil), which plays a critical role during transesterification and thereby controls the rate of reaction in the initial stage, and the use of heterogeneous catalysts which allows an easy and less expensive separation of the product. This thesis aims at studying the efficiency of a cocurrent downflow bubble column as a liquid-liquid contactor reactor in order to carry out the transesterification reaction of canola oil to biodiesel using heterogenous catalysis. The reactor provides great potential for chemical reactions that are limited by mass transfer and has several advantages over typical reactors used for transesterification. At the reactor inlet a high speed liquid flow is produced by venturi effect and this results in a vigorous agitation system with high shear and energy. This high mixing intensity allowed the production of biodiesel according to EN14214 (content greater than or equal of esters ≥ 96.5%), obtaining a 97% of esters in a time of 300 min at a temperature of 50 °C, using CaO from a rather low cost source (quicklime) as heterogeneous catalyst, with a catalyst loading of 8 % (w/w with respect to the reaction mixture oil-methanol), an oil : methanol molar ratio of 1 : 9. In order to understand the effect of the process variables the reaction was also studied in a batch reactor. The studied variables were reagents addition order, methanol quality, methanol-oil molar ratio, amount of catalyst, temperature dependence, type of catalyst and a reaction kinetic model was established. In general there is a minimal difference in the rate of reaction profiles between the lab scale STR and the pilot scale contactor column; beside the desearible content of FAME’s (97% EN14214) was achieve in both reactors after 300 min of reaction. It is worth to be mentioned that the reaction volume in the liquid-liquid contactor was about 24 times higher than the STR volume.proyecto 3685/2014 y al Consejo Nacional de Ciencia y Tecnología por el apoyo financiero y la formación académica a trasvés de la beca No. 383423, así como a la beca mixta para realizar estancias de investigación en Alemania con número (CVU/Becario): 627380/328718.Proyecto UAEM 3685/201

On the pseudolinear crossing number

A drawing of a graph is {\em pseudolinear} if there is a pseudoline arrangement such that each pseudoline contains exactly one edge of the drawing. The {\em pseudolinear crossing number} of a graph $G$ is the minimum number of pairwise crossings of edges in a pseudolinear drawing of $G$. We establish several facts on the pseudolinear crossing number, including its computational complexity and its relationship to the usual crossing number and to the rectilinear crossing number. This investigation was motivated by open questions and issues raised by Marcus Schaefer in his comprehensive survey of the many variants of the crossing number of a graph.Comment: 12 page

Finding Passion and Discovery in College Radio Talk Show – A \u3ci\u3eGeneseo Today\u3c/i\u3e Experience

Geneseo Today is an original WGSU public affairs program, featuring conversations with community and campus newsmakers about important issues, trends, and real-world topics affecting the local community, airing in two half-hour segments each weekend. As the Executive Producer and Host of Geneseo Today during the 2018–2019 academic year, I conducted several interviews for the episodes, and I edited and produced the half-hour episodes to broadcast on a twenty-mile radius. During the academic year, I encountered triumphs, downfalls, gained skills, memories, and life-long lessons that will serve me upon entering the workforce

The Struggle for Balance: Culture Care Worldview of Mexican Americans About Diabetes Mellitus

The purpose of this study was to describe, explain, and interpret perspectives, perceptions, meanings, symbols, and lifeways to explicate the culture care worldview about Diabetes Mellitus (DM) for Mexican American participants. Leininger\u27s Culture Care Diversity and Universality Theory served as an organizing framework Interviews were conducted with thirty Mexican American key participants without DM. Four phases of analysis of ethnonursing method revealed thirteen categories, five patterns and three themes. The categories were: Health; faith and religion; natural living; tranquility and stress; strong emotions; susto; immigration; life in US; family advice and support; cultural beliefs; treatments of diabetes; care; and communication. The patterns were a pattern of: Concern about DM with much confusion and uncertainties about the disease; maintaining balance and body defenses towards health; integrating self-care, generic and professional values in care; adaption to change and stressors; and valuing nursing and professional care. The themes American participants value balance and health yet have many uncertainties and concerns about Diabetes Mellitus that impact their culture care worldview; Mexican American participants\u27 culture care worldview of Diabetes Mellitus integrates self-care with generic and professional care values, beliefs and practices; and Mexican American participants\u27 culture care worldview of professional care of Diabetes Mellitus, emphasizes culturally acceptable, compassionate, personalized care, based on communication, mutual trust and respect, provided within the context of the family that supports the person\u27s struggle for balance, health, wellbeing and function. The Struggle for Balance: Culture Care Worldview of Mexican Americans about Diabetes Mellitus Pictorial Model, Hernandez © 2013 was abstracted by author, from study literature, findings and themes. Implications and recommendations for nursing theory, practice, education, policy and research were described

Surgical Site Infections and Hand Hygiene Discharge Teaching

Problem: During the span of a nine-month period, the PACU of a perioperative unit in an acute care hospital in the East Bay Area saw an incidence of 13 surgical site infections (SSIs). SSIs have been associated with negative patient health outcomes, diminished quality of life, and increasing healthcare costs. Context: The PACU consisted of 20 beds and a competent staff of registered nurses, medical assistants, patient care technicians (PCTs), and management staff. It served mostly adults from diverse backgrounds receiving elective and emergent surgeries. Intervention: A Standardized 3-Step Hand Hygiene Discharge Teaching model with nurse self-audits for every surgical patient with a surgical incision aims to improve the consistency of hand hygiene education provided during discharge for the patient to be able to care for their surgical incision at home. The anticipated outcome is a decrease in SSIs. Measures: The outcome measure for this project is the rate of SSI occurrences per 1000 patient days. The process measure is the percentage of PACU nurses completing the nurse self-audit sheet. The balancing measure includes the change of adding the nurse self-audit sheet and whether it is indirectly causing negative implications on other processes within the microsystem Results: After implementing the proposed intervention, it is anticipated that this acute care hospital will experience a significant decrease in SSIs with a 70% compliance rate of self-audit completion by the PACU nurses. Conclusion: Practicing proper hand hygiene is the simplest, least expensive and most important intervention patients can do to reduce infection. However, an inconsistency on hand hygiene education during the discharge process was observed within the PACU. Because of the organization’s policies and the short time frame allotted for this project, an actual intervention was not feasible. Therefore, future direction includes implementing the Standardized 3-Step Hand Hygiene Discharge Teaching model, performing periodic audits to further explore the influence of consistent hand hygiene discharge teaching over SSIs, and conducting observations on other days and shifts to further explore the validity of the observation results